Replacement coolant hoses

Hey everyone, Going to be replacing thermostat and water pump on my car at some stage pretty soon. The hoses look original, and I can see small amounts of 'crust' built up as they've weeped over time. I was going to replace the ones which look visibily perished, I don't suppose anyone has a list of the "common ones" (in case I miss one). Do people tend to replace with Porsche ones, or is there a good aftermarket kit? I couldn't see any and the originals lasted this long so I'll probably go for the same, though I might consider some worm type hose clips. Tobie.

First off the last time i ordered a hose spring clip Porsche sent a jubilee clip in a bag .. so i think we can safely say jubilee clips are fine Thermostat hose .. common to corrode on the inside .. don't need to change the pipe just remove it and clean the surfaces . Coolant pipes at the gearbox end .. they join to ally pipes that go up and over the fuel tank .. these leak at the joint .. it can be the ally has gone porous .. I tend to remove the pipe , clean the surface then a smear of loctite 5900 over the ally pipe and refit the hose as changing these pipes is a mission and also a ramp job . Other than that there is no set hoses that cause issues and hoses don't really need changing .. just cleaning .. bit of 5900 at times and refitting . Over engine coolant pipes .. ally .. main one to be aware of , small pipe n/s/r that goes to the bottle .. there is a metal bracket roughly inline with the n/s/r wheel .. It rots out in this bracket and it's an engine drop to replace .. doing one atm at work .. did one a few weeks ago .. be careful if you start digging and cleaning this part .. it might end in tears shall we say !!

DeMort, thank you for the helpful summary on coolant pipes. Regarding the smaller dia aluminium pipe which runs up to the header tank, is it feasible to cut out the leaking section and replace with hose, perhaps with double clips at each end?

I'm afraid that working for a garage im only ever allowed to replace components as we have to warranty what we do and as such i have never tried it ... Many people do use the cut and join method .. i have prior to working on Porsches .. This particular pipe and there is some access issues but i see no reason why you couldn't cut and run a rubber pipe .. If it was me i would be using x2 jubilee clips each end and also using loctite 5900 as a seal .

Thanks DeMort, I will give it a try, changing that pipe does not look easy!

Wonder if this loctite 5900 trick will work on the various rubber to alloy pipe connections under my 944 turbo bonnet? Still think I have a slight weep somewhere even after replacing and tightening all the clips.

Porsche sealants evolve over time .. We had the orange goo for air cooled engine rebuilds .. When i started at Porsche it was Dry bond that was the main sealer .. These days it's Loctite 5900 . 5900 is thicker than treacle .. i have to use a silicone gun to get it out of the tube .. but to be fair i'm only small and not that strong .. 9.5 stone to be exact !! Yup .. there's a reason i'm not an engine guy :hand: If you sand down a pipe surface so that its clean , smear some of this around the pipe then fit the rubber pipe over the top then its about as good as you can get without replacing pipes . The downside .. it will be a struggle to get the pipe off again if needed .. a 90 degree tool for removing coolant pipes will be needed .. which is what we use anyways .. at least i do to break the seal . Any silicone will in theory do the same as it will fill the holes / rough surface but 5900 is pretty good at this .

What do you use? Trying get consistent application of 5900 from a tube by hand was tough as it took so much effort just to squeeze it out. MC

I've just inserted a piece of rubber hose into the small dia aluminium pipe which runs up to the header tank. I went from just above the point where it is clipped to the body by a steel clip which corrodes and which can also corrode the al. pipe, down to a straight section after the point where I thought the leak might be. Not too difficult using a small tube cutter and Loctite with double S/S clips. The removed section of pipe is surprisingly thick walled and looked OK, but maybe it had become porous? So far so good but time will tell if it is a permanent repair!

I use a normal silicone sealant tube gun .. mine has a small end so it doesn't fall out .. I used a new tube of it today and to be fair i could push it out but to get an even bead i would use the gun .. dam stuff IS like thick treacle . Something like the image below.

Thanks deMort - a helpful & pragmatic approach as ever! I'll be tackling water pump, thermostat and will replace the idler bearings at the same time. Curiously I wondered which loctite you use for the bolts? I can't seem to find a definitive source of truth...

For things like water pump bolts then no sealant is needed . Do Not use thread lock on these bolts .. one day you might have to remove them !

I only spotted this thread yesterday and have always squeezed it it out by pushing on a thin hammer shaft, which has been a nightmare, it wasn't until last year when doing a Seat Ibiza timing chain and had to do both the timing cover and sump in one go that I needed to come up with something. I already had a regular silicone gun but worked out I could fit the tube in with a large washer in the end with the centre drilled out to take the cone of the 5900. I took some pics with the newly acquired but still unopened tube of Loctite today. I can't believe I struggled for so many years beforehand, :frustrated: