Swapping out a melted coolant hose... Vacuum coolant flush required?

Hi gang, Wishing you all a very Happy New Year, with plenty of smiles and fun miles. I figure I'd end this year with a question for you all; posting it to the 987 area although it really applies to most of our modern P-cars. Although my 987.2 Boxster 2.9L is finally going into the shop in over a week for a few expensive repairs that are above my pay grade (requiring a half-engine drop), I know that post-repair — I’ll need to deal with some sort of minor coolant leak that I can’t seem to find, let alone a hose swap. Especially now that I have a QuickJack in my garage and I’m finally back in action per wrenching (as far as I can currently tolerate the upcoming winter garage temps), I’d like to see if I could save some money and tackle the hose swap myself — let alone being able to handle my own routine coolant flushes — instead of having to resort to have the mechanic do it. Here’s the backstory: Since I got the car two years ago, there has been a minor coolant smell coming from engine bay (side vents) after a long drive, but I can’t source it. The obvious culprit is a single coolant hose that was damaged by CHF-11 (power steering oil) that chronically dripped onto the hose and melted it. Assuming I can drain and fill the system, that seems like it should be an easy swap and obviously first ruling out first. (See the attached photo — it’s stained with oil and test powder from an oil leak test — a key reason why the car has to go into the shop.) Unlike my coolant cap in my previous ’05 987.1S, I’m almost positive that it is not that. I’ve largely ruled out the cap as the culprit: the cap is the newest model, there’s no coolant smell in the trunk post-drive, and there’s no condensation or crusting present (as there was with my original bad 987.1 coolant cap). I did a cold pressure test back in the spring, and couldn’t find the leak anywhere in the car. Meanwhile, the system wasn’t holding a vacuum, and there was no puddle of coolant anywhere. I suspect that the leak is very minor and may be from weeping from the affected hose. The coolant seemed very lightly low a year ago, so I barely topped it off. Again, there has been no major coolant loss or low-coolant messages. Anyhow, I do have the replacement hose in-hand, plus an extra O-ring in case I need it (I wasn’t sure if the extra O-ring was necessary on the female end). I figure that if I try to remove the hose, clearly coolant will spill out — but it’s unclear as to how much. My key concern that even if I caught a bit of the spilled coolant, replaced the hose, and sealed it back up, and topped off whatever was lost — there would now be air in the system and our 98X are notorious for air locks. I figure that since I don’t know the car’s long-term history, maybe a preventive coolant flush with some Xerex G40 might be in order anyhow and I’ll have to deal with that at some point (including my BMW E30). First, for draining the system, I figure I’d do the normal procedures. But apparently, getting all the old coolant out of the system is supposed to be quite challenging. Meanwhile, I do happen to have on-hand a HIGH volume, low pressure “Cyclone” pool line blower that I used to use to drain the pipes of my folks’ pool. Instead of an air compressor (low volume, HIGH pressure) — I figure it should safely clear the system pretty quickly once it’s done draining. It’s kind of like the blower of a Shop Vac, but on steroids. However, I'm assuming I'd need to disconnect a thermostat (to open the system)? Any thoughts on this? Next, I’d pour in a few gallons of distilled water to fill it, and then drain that out (using the blower in the end to clear out anything remaining). Finally, I’d attempt the vacuum refill (Schwaben, Airlift, OEM Tools tool), as apparently they do a fantastic job. The key issue is that my small air compressor goes up to 110psi, but only has a paltry 0.8 CFM (I think I’d need something far more powerful as these refill systems require a constant 90 psi). As I have more time than money, I'd be fine with seeing if my small compressor would create the vacuum — even just up to 10” instead of 28" (or whatever it is supposed to be) — and letting it go down to zero as a partial refill — and then running the vacuum again. I’d really prefer not to have to buy another and larger air compressor if necessary. Thoughts? Would love your input, gang. Cheers and Happy Holidays!

Wow...that hose really did melt. DIdn't realize the power steering fluid was that corrosive. The electric rack in the 981 may not have the feel of the 987's hydraulic unit, but at least we don't need to worry about melting coolant hoses. HNY!!!

Happy New Year to you too, @Platinum5150 -- It is most certainly corrosive to rubber; it's an oil and not like a normal power steering fluid in other cars. I've seen this come up a few times, and I believe it has something to do with the hoses not being crimped well from the factory. I thought of having the PS hose inexpensively rebuilt, but I just need it done and am just going to have it replaced at this point. The 981 and 987 are so different largely because of the power steering -- different enough that I'm currently enjoying driving both cars. If you want a better steering feel, try coding your 981 with the GT3 setting with a PIWIS -- best free hack I've done to the car. Cheers.

Not to hijack your thread, but I thought I read that a large part of the GT3 upgrade is less steering effort. Not so sure I want Buick level assist, but for increased road feel could be a worthwhile tradeoff.

Thread not hijacked! To me, the GT3 upgrade was more (not less) steering effort. Definitely felt more connected with the road. More tiring over super-long trips, but I left it as-is and am happy with it. YMMV.

Now that sounds very intriguing to me! I know Ernest has offered to do this upgrade, and I think he may be about a 4 hr drive for me, so may be something to consider for sure. Back to your regularly scheduled programming

I want to know what happened to your 2.9. 987.2 that requires engine removal?

Happy New Year, @Ric_in_RVA -- Thankfully nothing catastrophic. Again, mine has 256K+ miles on the clock, so some leaks are to be expected at this point. It will require a partial engine drop to (1) replace the left valve cover gasket (our 987s don't use a real solid gasket) due to oil dripping, and (2) replacement of the oil vacuum pump by the firewall -- also due to additional oil leaking. Meanwhile, my 987.2 has performed brilliantly since I got it two years ago and the engine recently got an amazing bill of health from the Blackstone oil report , but it really needs to be done at this point and these projects are both time consuming and costly. Plus the oil leaks are messy, and I really don't like the risk of oil dripping on the hot cats and catching fire. I also need to have the PS hose replaced, but that part won't require the partial engine drop. Fingers crossed all these repairs won't break the bank -- hence my hoping to field the coolant issues myself if at all possible.

256000 MILES IS AMAZING! Give that 9A1 some love and slap her back in there and go for 500k! I feel much better at 107000

Thanks! I'll likely be writing a whole story for Food Biker / Road Feast about this car; it's really pretty special and the stories that have tied everything together to date is worth compiling. Stay tuned!

Have you inspected your water pump? Water pumps usually have a very small weeping hole where coolant will start to escape when the pump is reaching end of life. At 256K maybe you should replace all your coolant hoses, including the front ones, in one go and be done with it.

Good points, @Vortex Ring State -- I have checked the pump, but didn't see anything notable. If someone has a picture of the "very small weeping hole" location, I'd be very curious to see where that might be as surely that's a repeatable point of failure that is bound to crop up in many of our cars. Before I rip out all the hoses and do a major replacement, I'll be trying to get the car's past history from Porsche Atlanta. I'm fairly confident that everything that needed to be replaced was already done -- as it seems like it was dealer serviced for its first ~242K miles or so. So I'm guessing that surely the pump was replaced already at an earlier service. From the VAL from the PIWIS, it's clear that this car was not thrashed and the mileage racked up was likely commuting miles -- so I'm expecting the lifespan of some internals to hang in there longer than the stated service mileage. Who knows... If time and money (especially the latter) were of no object, I'd consider prophylactically doing the swap-out. Meanwhile, given that there are no clear signs of weeping/corrosion/etc., I'm going to likely punt. There's a school of thought that the modern hoses are now built to last -- so we'll see.

If the cooling system is opened and you lose some coolant, you'll need to do a bleed. A flush is not necessarily needed, depending on the age of the coolant in the car. On my car I used the Zerex G40 (ordered from my local NAPA), it has been great and was not nearly as pricey as the Porsche -branded stuff. I bought and used an AirLift for the filling and bleeding. It worked great and I was thrilled with how easy and efficient it was. I used my home compressor (13 gallon, 4 HP) and it was plenty. IIRC, I think the AirLift just needs a constant 25 psi.

Thanks, @racergreg - This is a huge help. Again, I don't know how old the coolant is but I'm guessing 2016-ish when the owner sold it back to the dealer and it then went to auction. So, I have 3x gallons of Xerex G40 literally on the way from NAPA ($20/gal on sale), so that's not too terrible. Just figure that if I'm already doing this, it's probably not a bad idea. This being said, I figure I'd invest in an AirLift. I've watched multiple videos on using these to refill, but how do use these to definitively purge the system? I also figure I'd try my smaller compressor (even if it requires multiple refills to get the vacuum all the way up) first. Mine can do a constant 25psi, but certainly not 90psi (as most require). Also, if I just wanted to bleed out the air with the AirLift (no flush) to get rid of the air pocket created by the hose replacement, how would I do that? Thanks in advance!

@foodbiker Good points. That explains things better. I doubt very much you can see the weeping hole. It looks like it would be hidden by the pulley. You would have to pull the drive belt and then the water pump pulley. Probably a wild goose chase anyways.

Thanks. (And a Happy New Year, BTW) Again, this is a situation per the coolant where it's not catastrophic...no significant coolant loss over time... no error messages... just the coolant smell... and hopefully just replacing that single hose will do it. This being said, I'll make sure to have my mechanic who's going to be doing the deep dive look at the water pump to see if it might need attention. BTW - I did read the Airlift instructions, and there's nothing about using it to drain the coolant...just to refill it once it's completely evacuated...

No, you don't use the AirLift to drain, gravity will do that for you - have a big bucket ready, there's a lot in there! So just drain the old stuff from the lowest point you can. Then replace your hoses/connectors/whatever (good time to do the water pump if it's due) and button it all back up. The AirLift creates a vacuum in the entire system, then it has a valved hose that you put into a bucket of new coolant mix. The vacuum sucks the coolant into all the nooks and crannies, preventing trapped air. Here's how I set it up in my car - I put the bucket of coolant mix as high as I could to make it easier for the AirLift to pull it in. Notice the pressure gauge is just above 25 psi. The AirLift has a big rubber stopper that just gets wedged into the mouth of the coolant reservoir. Works like a charm!

Love it, @racergreg - This will be a HUGE help! The photos are fantastic, and I'm sold on the Airlift. Makes sense about how it works. A few other questions come to mind, if you have a second: When draining, it will wind up being over 6 gallons (so I figure I'll use a Sterilite or Rubbermaid tub?) Meanwhile, how do you get the rest of the fluid out? Apparently, there's plenty that is stuck in the lines? What about the heater core? Do I need to run the car or anything with the heat on full blast and/or disconnect the thermostat? Just want to get any extra coolant purged, especially if I do a distilled water flush in the process. I figure I will give my small air compressor a try first -- even if it fails to go all the way up to the upper 20s" for the vacuum. From what I understand (from another forum where old hoses on an older P-car might benefit by not being vacuumed out to such a high vacuum, maybe I could do it in a few steps: First pull a modest vacuum with the compressor (maybe 10") Let the system suck in as much as it can with the pressure dropping down to 0" Shut off the valve to the coolant tub (making sure the refill coolant tub run does not run dry, but restart the compressor again for another 10" or whatever and then continue sucking up more coolant Let that run down to 0" and ideally I'll see the coolant filling in the reservoir With the vacuum fill, do I need to burp it (bleeder valve) after driving it? Or is it really simply good to go? Finally, which Airlift did you pick up? I know there's a plastic on for about $100, and then another one that has more metal for about $40 more? So many thanks, @racergreg !!!

The airlift I bought and gave to my mechanic came from Harbor Freight , around $80 IIRC. It is worth every penny and is quite a well-built and easy-to-use device.

I remember that, @deilenberger - let alone very cool that you gave it to your mechanic. Good to hear that this is a squarely doable project.

So, here's the update... First, I've squarely decided that I'm going to attempt the coolant hose and coolant drain myself. As I've replaced stubborn high pressure brake lines on my E30 convertible surely larger low-pressure coolant hoses in good shape shouldn’t be as difficult. I spoke with my mechanic, and the car is going into the shop on Monday as planned -- and I'll manage the coolant stuff afterwards. We both agreed that the swap and bleed should be in my wheelhouse, but I'll be packing the car with the 3 gallons of Xerex G40 coolant and parts, just in case it really makes sense for him to do it -- especially if he spots something else deep in there while the engine is half-dropped. It’s really great to find a mechanic who will both work with me and understands my budget constraints, as opposed to mechanics who try to drum up business and think that those of us enthusiasts have no place getting under the hood. Again, I'm convinced about the Airlift and it'll be a solid investment. Any thoughts as to which version (plastic/metal), please chime in. Not only as will my wife's MINI Countryman and my 981 Outlaw need it in a few years time, I’ve recently realized that my E30 will also need a full coolant flush shortly. As I'm busy prepping the E30 for a BaT auction early this spring, I need to correct the weak heat in the cabin and a foam seal blowing into the passenger footwell -- both signs pointing to a failing heater core -- which is apparently a bear of a job but not impossible -- especially if the coolant lines are fully purged. Plus, I checked my records and the last coolant swap (G48) was 10 years ago almost to the month. As M20 engines are apparently a PITA to refill, the Airlift certainly seems like the way to go. Finally, I just watched fellow moderator @jjrichar 's amazing coolant bleed and fill video for the 981. Seeing that the 987.2 is also a 9A1 engine, it appeared to be a direct instruction for mine as opposed to a 987.1. Very cool and even more reason for me to attempt this myself. ( @jjchar - Any chance you might be able to weigh in on my earlier questions in the thread?) Thanks, gents! Cheers and thanks to everyone who has continued to weigh in here.

My perspective on your questions. The plastic Airlift tool works a treat. I can't imagine the metal one working better. I think they are simply a case of providing a tool for the pro and DIYer just in case your shop apprentice wants to play football with the tool. Compressor capacity isn't such a big deal. I'd suggest adjusting the output pressure to 120 psi, as this it the thing that makes the difference. When activating the tool you need to only have it active when the pressure is a maximum. Activate at 120psi, and as the pressure slowly decays, stop activating the Airlift tool until the pressure rises again to the maximum. The key is to not allow the compressor to kick off line, but keep it going just below this point. With a low capacity compressor you will need to be activating/deactivating the tool over and over keeping the pressure at this maximum level in order to achieve the best vacuum possible. Having the maximum vacuum is the key to effective filling of the system. More vacuum, less air. To flush the system, I simply use tap water. I'm fortunate to live in a place where the tap water is very soft and has few contaminants. What contaminants are there are countered by the coolant chemistry. So to flush the old coolant out I'm simply going to fill with fresh water, using the same method with the Airlift tool and then repeat until I can see all the coolant is gone. It's good practice using the tool and filling so you are very comfortable when finally filing with coolant. Doing the fill with a lower vacuum step by step won't work. You will simply be sucking coolant from the reservoir into the tool the next time. It needs to be done as one process. I can't see the drain on the 987 being too different from the 981 . Just use the method I show on the video. To really drain the most possible I'd suggest disconnecting the lower hoses at the radiators afterwards. I'd be checking the cap for correct operation. I made a video on this. Pretty easy to pull apart and check. It's something that many overlook and is a critical part of system operation. I can't stress enough that the key to filling and effective bleeding is achieving the best vacuum you can using the tool so that maximum coolant/minimum air is in the system prior to bleeding. Practicing your technique to achieve this is super important. Prior to working out the method I did, I had a lot of issues bleeding and not overheating. After sorting my technique it's honestly a no brainer.

This is the device we used to vacuum out my cooling system on the 987.2 : Cooling System Test and Refill Kit It worked fine. the chap at Harbor Freight behind the register made it a point to tell me that it can be returned up to 90 days of purchase for a full refund. I think he might have been suggesting sometthing. I didn't return it - instead I gifted it to my mechanic since he's very thrifty and would have happily spent a few hours (on my tab) bleeding the system manually. Just paying the $80+tax probably saved me 2 hours of labor at around $150/hour. I wonder if somewhere like Autozone or Advance Auto - who have tool loan programs - have one of these in their loaning pool (if you buy the coolant from them..)? Might be worth asking.

@jjrichar - Sorry for my delayed reply here. Simply a brilliant explanation and a huge thanks for taking the time to write all that up. The water here in Cambridge (Boston) has some minerals in it but I think I'll do as you say and just practice a bit with tap water. I mean, I get boiler scale in our humidifier and espresso machine, but that's over a period of time. I'll just go for it. Additionally, I think I'll try my small compressor and see if I can get the vacuum all the way down. If I can, I'm golden -- but will go buy a used one locally if it does not pull enough vacuum. Better to test via that (and a leak) BEFORE messing around with the antifreeze. Again, you're a tremendous help here to myself and to all here on P9. @deilenberger - Yes, I remember you had the Maddox HF version and will keep it in mind, to be sure. It may be a "buy once cry once" situation... and I know I'll need it squarely for two jobs in a bit. 987.2 went in for the service yesterday. 2 hour train ride, plus the subway and a long walk to get back home -- but the wrench seems like he really knows what he's doing. I've way overthought such repairs for at least a year now, but my wallet has dictated my being super-careful (it admittedly almost seemed like a "game over" for the car at one point per a potential need for an engine swap -- and I was apparently wrong from what I understand). Looking forward to having all this fixed up, and then I'll manage the coolant soon. Thanks to everyone who has chimed in here.

Just wanted to toss out a quick follow-up on the vacuum coolant fill thread. "Cherry" (aka, Cherry Bomb) is finally back home as of this past Tuesday. The drive home was admittedly a bit hairy, as the car skidded at high speed for about roughly 1.5 seconds in interstate traffic -- due to a quick road freeze setting in at the end of a snowstorm. I could have sworn that out of the corner of my eye, the PSM light blinked once before all this happened and I should have paid attention to it... I shrugged it off. As I rarely skid ever, the PSM light did not flash when I felt the skidding and I'm assuming that didn't happen as I may not have been accelerating at that point. All in all, I'm glad that both the car and myself are safely home. I will unabashedly gush about the automotive prodigy that is Jarett Hurteau at Revenant Motorsports in another thread. He saved my car without destroying my wallet, and there's no more oil leaking from the valve cover and CHF-11 from the power steering system. The steering felt amazing on the drive home (aside from that icy moment!!!) and I can't wait to get back out there. After many weeks of fretting about which system to buy, and throughly watching @jjrichar 's amazing video, I figured I'd spring for the newer and less expensive Uview "Airlift II" system -- but quite a few people have mentioned that the unit's push-button is difficult to use if you own a small air compressor like mine (0.8 SCFM) as one's thumb gets tired holding down the push-button valve. I was sorely tempted by multiple Chinese clones in the $30-$50 range, A bunch of mid-priced ones (Schwaben, Harbor Freight (Maddox), OEM Tools) for around $80, the base Airlift II for around $100 (plastic version), and even a used Matco system (which would require a universal adapter) on Facebook Marketplace around $140. FWIW, the lower the price, the more registered complaints about leaks and frustration of not being able to hold a tight seal. Anyhow, I'm guessing that like many people, this is one of those tools that most of us home wrenches would use every few years or so (30K miles or maybe 5 years) as "lifetime coolant" really isn't a thing. What's doubly forcing my hand here is my currently prepping my E30 convertible for sale this year, and I suspect it'll need a new heater core -- which would also necessitate a flush -- which was 10 years ago (time flies!) according to my records. Plus, I'd surely use it at some point on the other two cars -- so an investment on a solid unit seems to make sense. Ultimately, I may have lucked out -- as I just found and bought an affordable and used Airlift (original) on eBay -- and I'll give it a go once it arrives in about a week. What I did admittedly like that the reviews of the original Airlift were outstanding, and someone actually posted a video showing how someone could use this exact model Airlift with the exact same low SCFM (0.8) that my air compressor provides. Again, I have far more time than money here, and really don't relish the idea of having to buy a separate air compressor just for my having to do a coolant change. Basically, one plugs in a hand-grip air pressure valve (easier than the Airlift II's push button) inline -- which I already had from the one I use to inflate my tires. Given that surely my P-car uses a lot more coolant than the one in this video, at least it'll theoretically be doable to ultimately pull the pressure down well into the green zone -- without wearing out my thumb. Plus, I don't want to disturb my neighbors with a larger air compressor and fingers crossed this will quietly work. I'm going to take @jjrichar 's suggestion to practice with water first -- which sounds great for the actual flush. Then, I'll be sure to do the same thing on the E30 when all is said and done...and get a new heater core in there! (A difficult install, but I think I've done worse and it shouldn't be messy if I blow out the system first...) Anyhow, stay tuned and I'll let you guys know how my adventures in coolant go.

I use a basic spring clamp like the one below on the Airlift press button. I just put it in place and walk away. A few minutes later I'll have about 28 inHg of vacuum. Got sick of pressing the button and having a sore thumb.

Absolutely brilliant, @jjrichar !!!

I have been out of the country for the last couple of weeks, sorry I didn't see your questions! Sounds like you have it squared away, though, thanks to the other great contributors here. I'm sure you'll handle the job without any big problems.

Hope the travel has fun, @racergreg whether it was for work or pleasure! No apologies necessary; we all get very busy at times and your suggestions will be an immense help. Hopefully I'm on the right track, and I believe that the used Airlift (original version, UView model 550000) be arriving in a bit over a week. I forgot that you also had great success with the Airlift II, which is great. Glad I scored the used one I found on eBay and let's hope it similarly works a treat. I do have a question for you all. Although assuming I will eventually get the vacuum down to the -25" Hg (well in the green zone on the pressure gauge) with my low SCFM air compressor, how will I know if the system is entirely full -- other than a visual inspection of the coolant tank? Also, per the coolant release valve, if/when do I open the bail to burp any minor air out? I never quite understood the whole bail thing, and I want to know when I can safely close up the engine bay and restore the interior carpeting. I'm guessing that I'll leave it closed and after a drive, go back in after it has cooled down -- and then release and latch bail with the hope that any excess air I missed will let itself out. Or is this really going to be a one-and-done deal where I won't have to keep checking it? Thanks to all!