Remote reservoir woes

[tmoretta]

Been having trouble with leakage/seepage from my "Replicaparts.com" supplied remote reservoir kit. I first noticed a sizable leak last year on my completed and running 818S. I removed the wiper kit to gain access and then added clamps to the hoses at all connections. Seemed better for awhile - but, now there is seepage again at both the clutch and brake reservoirs. I am wondering if the very soft supplied hoses are disintegrating from the brake fluid. I will once again disassemble and try to determine the cause of the leakage. In the end I may have to trash the remote system and revert to the original plastic reservoirs. Any ideas/suggestions/fixes?

[Bob_n_Cincy]

A lot of rubber based hoses are not compatible with brake fluid.
Personally, I would go with clear tygon 2375 so you can see if you have any bubbles in the system.

https://www.amazon.com/Tygon-Clear-Reservoir-6-35mm-Brembo/dp/B0117SUVNO

[Hindsight]

tmoretta, one other person here complained about the exact same issue, however, I have the remote reservoir as well and have not had the issue you guys did. Did you by chance use dot 5 brake fluid? That might be why if so. I used dot 4.

I ordered some new hose from McMaster. You can use several different kinds but the Tygon Bob mentioned will work great, as will EPDM. You want 3/8" ID tubing.

EPDM and Tygon from McMaster:
https://www.mcmaster.com/#9776T9
https://www.mcmaster.com/#5103K36

Consider clamping all the hoses with constant tension spring steel hose clamps, that way you can still use a pressure bleeder. I've been running with the above tubing and clamps for almost a year with no leakage seeping. The only reason I replaced the tubing on mine was because I wanted to route my lines differently and ran out of hose from Mike's kit.

[tmoretta]

I had a chance to get visual access to the systems today. Seems like the supplied plastic threaded elbows are leaking at the joint with the machined aluminum. I am going to try to source some replacement (non plastic) fittings.

[Hindsight]

The plastic fittings should be fine for use with brake fluid. I think they are the same material as the reservoir (might be nylon, I forget). You do have to really tighten the fittings tight into the aluminum to get a seal.

[K3LAG]

Mine leaks too. Mine seems to be leaking from the machined fittings on the brake master cylinder not being tight enough. I was never happy with the idea of zip ties to attach the hold down plate for them. I made these yesterday but haven't had a chance to test them yet. The blue plastic parts are 3d printed versions used for testing. I made them since my parts are on my car. Obviously the bolts are a bit tight for the plastic parts.

62457

[lance corsi]

I had a chance to get visual access to the systems today. Seems like the supplied plastic threaded elbows are leaking at the joint with the machined aluminum. I am going to try to source some replacement (non plastic) fittings.

Try applying some loctite to the cleaned threads of the elbow. I've had really good luck with locktite on difficult to seal threads. Also, I concur with Bob that the tygon tubing is best for this application. I bought some with a Teflon lining, which is good for most chemical contact. I will be using dot 5 fluid in my system since everything is new, but according to what I read, dot 5 fluid is compatible with seals etc, but should not be mixed with dot4 or dot3 fluids because the reaction between the two fluids causes the liquid to gel, rendering inoperable brakes.

[Aero STI]

I have the replicaparts piece. It's getting installed soon. I'm going straight to the tygon tubing. Thanks for the advice.

[bompus]

Looking up Tygon information, I find a lot of motorcycle folks tried to use it ( Tygon 2375 = bad? but F-4040-A = better? ) , but based on my quick searches, the Tygon 2375 at least seeped/leaked for them. Who knows what percentage have an issue with it vs. not, but it seems like most OEM use EPDM rubber hose for these types of things, and it's less expensive. Not transparent hose, but that isn't a huge deal for me.

[michael everson]

Not sure why some of you are having problems and some now. The hose supplied is EDPM from McMaster-Carr. Mine never leaked. My neighbors leaked all the time. Seemed like it was bleeding right through the hose. He was using DOT 5 fluid. If I can find a decent replacement hose, I will gladly supply it to those that are affected.
Mike

[mikeinatlanta]

Re the hose: Tygon 2375 is not compatible with DOT 3 or 4 brake fluid. Nevermind what the forums say, check with the manufacturer. The ONLY low pressure hose recommended by Gates for DOT 3 or 4 is EPDM.

Re the fittings: What is the connection design that is leaking? If pipe thread, you need to use a pipe thread sealant rated for DOT 3 or 4. The Loctite thread sealers commonly out there are not. Use something specifically designed for brake fluid like Permatex 59214. Any type of flared fitting should never have sealer applied.

If a fitting is banjo: Make sure all sealing surfaces are free of heavy machining marks or scratches. Concentric machining groves are ok, but never any sort of cross seal grooves. Make sure you use new sealing washers with each tightening.

If the fitting is O-ring sealed, make sure the surfaces are properly prepped and free of sharp edges. Make sure the O-ring is EPDM, properly sized for the gap, and use a quality O-ring lube such as Parker O-Lube to install.

If you are dealing with a barbed hose fitting. Ensure that it is free of any scratches on the barbs. If a cast plastic barbed fitting, ensure there is no mold line on the barbs. It can be a pain, but mold lines on cheap cast plastic barbed fitting barbs must be sanded smooth and polished. Make sure any clamps used on a barbed fitting provide an even, ROUND, 360 degree clamping force. Never use cheap worm drive clamps.

RE the reservoir: Make sure all sealing surfaces are in "new" condition. Use a strong light and magnifier. No scratch is too small for a leak to develop.

Do all of the above and you will be leak free.

[lance corsi]

You may even want to replace those hokey plastic elbows with something more substantial. Heat and age degrade plastics.

[STiPWRD]

Mine leaks too. Mine seems to be leaking from the machined fittings on the brake master cylinder not being tight enough. I was never happy with the idea of zip ties to attach the hold down plate for them.
I had a slow leak at this exact same location due to the lack of pressure on the metal brace zip tied to the master cylinder. I replaced the zip tie with one or two U-bolts (similar to what Larry did) except I reused the metal bracket but had to trip it a little bit. It seems to have stopped the leak but it was tough to get in there with the wind shield in place.

[Hindsight]

I had the same issue. I made my own bracket that had a plate on it which would allow me to re-use the factory spring pin that secures it to the master cylinder.

http://i.imgur.com/N7rXStOh.jpg

http://i.imgur.com/qev9zIjh.jpg

[SixStar]

We have a car in the shop now that's also leaking from these relocated reservoirs.

[K3LAG]

We have a car in the shop now that's also leaking from these relocated reservoirs.

Yep. That's mine. See post #6 above. I'm going to drop them off later in the week.

Larry

[idf]

I've had no leaks with mine 18 months after installation. I used parts as supplied by Mike but added steel spring hose clamps to the connections and used safety wire in place of the wire tie to hold the plate on top of the brake master cylinder. Dot 4 fluid.