Brake Fluid Leak

Went out to get started on replacing the transmission mount this morning and found brake fluid by my passenger front tire. Got it jacked up and pulled the wheel off. There's brake fluid everywhere in the wheel well. The potential sources of the leak based on the spray seem to be the two ends of the flexible line and the hard line going into the caliper. The flex line attachment to the car seems to be the highest potential. I suppose the flex line itself would also be possible. Flex line attachment to car I had my wife pump the brakes, but no leak or even seepage was visible at any of the potential points. I even started the car to get the assist and still nothing. Anything else I can try to isolate the potential source? Right now I'm leaning towards just replacing the flex line and seeing if I still have an issue. Another question on that, if I just replace this line, I should only need to bleed this caliper, right? Or I guess is it possible that air gets back into the system and I have to bleed all 4?

Are you sure that's brake fluid? Did you check the fluid level in the master cylinder?

The only other potentially green fluid would be power steering. But I don't see any way for that to get here. And my brake fluid level is a bit lower than I remember. Here's a shot the PS lines up front and the puddling in the LCA:

I just redid the brakes on mine, including new flex lines. I didn't want to over torque the fittings, so I made them good and snug. They ended up leaking a little and I had to torque them some more. It looks like there may be some leakage at the fitting, but that doesn't explain some of the wetness up high. If the flex lines are original or old, I would consider replacing them.

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Did they leak at the flex to hard line connection I'm showing in the first pic? The wetness generally everywhere can be explained by spray caused by it dripping in the wheel and getting spun around. Unfortunately, it's making it hard for me to figure out where it started. And I'm too afraid of a total braking loss to drive it until I do figure it out.

That's Pentosin power steering fluid...

But it looks like what's in my brake fluid reservoir. Also, how could power steering fluid get over here from the rack?

Oh crap. Someone put ps fluid in as brake fluid?

Hmmmmm, maybe... I've had a seal blow out on my steering rack- looked just like what you've got. I can't comment on the brake fluid as I've never seen that...

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Yes, the leak was at the fitting. It was noticable because the hard pipe below became wet and you could see liquid at the fitting, like yours.

I�ve only seen clear/gold fluid and blue, never green. Is that CHF11S power steering fluid in the brake reservoir? If it is the brakes, seems like you should be able to see it leak/spray if you have someone step on the pedal (or use a motive power bleeder) to pressurize the system.

Try starting the engine, pushing the brakes (hard!), and turn the wheel as far as it will go either direction and then look for leaks. Turning all the way to the lock forces the P/S to max pressure. Do not do this for more than a minute or so. It is a LOT of pressure. If you have a P/S leak it will show then. Turning the wheel will also flex the brake line. Also take a look at the caliper. Possibly coming from a leaky caliper piston? And I also have NEVER seen green brake fluid. That is concerning to me. Pentosin is the same color which makes this very very concerning. I have never seen the effects of Pentosin in a brake system. However at least twice a year, at my shop, we see customer put regular P/S fluid in the master cylinder. Once this is done EVERY rubber and hydraulic part MUST be replaced. This is due to the petroleum swells the rubber and damages the system. Flush does nothing to help. Two of the easiest ways to confirm (not sure if Pentosin is the same) is the rubber seal on the master cylinder cap swells up amd it can be difficult to reinstall. The other is to remove a large sample of fluid in a clean clear container. The two fluids - brake fluid and p/s fluid will seperate after a few minutes. Again i have never seen Pentosin be put in a master so i am not sure if the effects would be the same.

Thanks for all the input! Bit of scary morning thinking I had to replace all the rubber bits in my brakes. But my reading seemed to indicate that PS fluid in the brakes would quickly lead to problems, and I've had this car for ~2 months and over 1k miles with no issue. So it seemed unlikely. Here's my verification: A flavor injector makes a good brake fluid removal tool Pentosin CHF 11S on the left. Fluid from brake reservoir on the right. And just for funsies, mixing them together. Pentosin looks to float on the top. Still don't know where the PO found green brake fluid. So dporto for the win with correctly identifying Pentosin CHF 11S. And Mbren, thanks for the great tips on locating the source of the PS fluid. I'm still a bit befuddled as there does not seem to be a line carrying PS fluid with any hint of a leak. Will try your recommendations first thing tomorrow and update with the solution to this mystery.

You may have a pin hole leak in a break line that a slight pump on the breaks from your wife may not make it show. Have her hold her foot on the pedal with pressure after she pumps it a few times with the car running. Good luck

The fluid in my brake reservoir was green as well. I'm pretty confident that you have ATE racing brake fluid as that is what is in mine. I would recommend replacing your flexible brake lines with new stainless ones. Then buy a Motive bleeder if you don't have one.

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Last I knew ATE brake fluid was blue or gold, not green. That might have changed? As I recall, the idea was if you alternated between the colors, you�d know when the system was fully flushed when the new color came through clean. If your brake fluid isn�t clear yellow (amber) or dark blue, I�d flush it with known good brake fluid from new sealed containers.

Yeah, you can do whatever makes you comfortable. When I flushed my brake system I ordered two litres of ATE type 200 racing quality. One was green one was amber. Both dot 4. Then Goodridge brake lines. I'm not too worried about the color. Don't know how you could specify anyhow.

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Because it is called ATE Super Blue... ​​​​​​​

Back in the late 60’s when I was a kid and first starting working on cars we had a Hillman Super Minx. Some how when working on the car we accidentally put knee-action fluid in the brake system. Needless to say this was not a great thing to do��. I am not sure of the characteristics of Pentosin Power Steering fluid but I would think that it would greatly compromise the braking system if it got beyond the reservoir .

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Unfortunately the blue is no longer available, something to do with US and EU regulations. I used to alternate the blue and the Amber when flushing the system but no more.

Ok so as I showed above, I definitely don't have Pentosin in the brake reservoir. It's definitely brake fluid - just happens to be green. But back to the main issue. The leak. It's green, but it's greener than the brake fluid. I poured a bit of Pentosin in the LCA next to some of the leaked fluid and it's a clear match. So Pentosin CHF 11S is our fluid leak. I got it up on stands and tested the steering and the brakes again (just for good measure). No leaks. I had to move the car a bit before that to get it centered for the jacking it up in my garage and no additional fluid leaked during that time either. I'm totally stumped by this. I don't see anything that could have squirted this fluid in here. The steering rack looks perfect, and I don't see any lines carrying Pentosin that run by this passenger front wheel well. I'm thinking I'll just take it out for some short drives testing a few things and then coming right back to check for more leaks. Yellow is the leak pooled in the LCA. Red is Pentosin CHF 11S. I think we have a match Just double confirmation. Yellow again is the leak. Blue is the fluid from the brake reservoir. Definitely a different/lighter green. Just a mess of fluid sprayed everywhere in here. Very dry in the area around the steering connection No leaks down the channel with the steering rack

Good pictures. But i cant get a good look at the bellow boot at the rack where the tie rod goes in. When racks fail they leak fluid into bellow boot. The bellow boot is only a dust boot and should not have any fluid in it. Possibly the fluid came out where the tie rod comes out and leaked down?

Your wish is my command. I would take that end thing off but it looks like something that I'd break in the process. Instead I gave the boot a nice squeeze and feel down. Feels normal and no evidence of fluid on either end.

Ok ok ok......my last thought......strut blew out! Its got to be strut fluid!

Perhaps you can clean up everything thoroughly with brake cleaner then drive it for a day and re-check. May give you better clues where the actual leak is.

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I think we have a winner!. I did read that Pentosin is a shock fluid in the spec sheet: Pentosin CHF 11S is a synthetic high performance hydraulic fluid for lifetime application in modern vehicle aggregates. Pentosin CHF 11S is especially designed for hydraulics in the automotive industry with the highest technical requirements such as in: power steering, level control, shock absorber... But I thought, what are the chances it's used on these specific Bilsteins. I'm very curious if anyone else has experience with blow shock absorbers? Some supporting evidence I have. The drivers side wheel well area is much dirtier than the passenger side with caked dirt on most surfaces. I think this shock blew a while ago and the fluid has been collecting dirt ever since. In addition, the coolant hoses near there have kind of a sticky substance on them. Passenger side front shock top mount. No bump stop on either side. Rears look like the stops are about to fall off because they are so deteriorated. Drivers side under the boot Passenger side under the boot. I think this is the source of the leak. Drivers side general grime build up likely from the dirt caking into the shock fluid that dumped everywhere. I'm guessing these sticky spots on the drivers side coolant hoses are from the shock fluid that's reacted with the hose material. Another shot of where the coolant hoses were likely exposed to the same fluid. Thinking these should be replaced sooner rather than later.

Ha ha....nailed it! Seeing these pics under the shock boots sealed it for me. The reason i guessed it was i was going thru all your prior pics thinking. Then i saw how the fluid was all over the shock body. This is actually great news. Car is still drivable at least. Sounds like its time for coilovers! I would clean it all up ASAP. Rubber parts don't take kindly to thoses types of fluids and tend to swell and break down quickly.

I rebuilt both sides of the front end suspension because the passenger side shock blew all the oil out and it was a mess.....just like this example. Time for new shocks.

I�ve been searching all afternoon on this! Same thing; brake fluid is fine, power steering is dry, antifreeze is a different color. Green fluid everywhere but no obvious source.