Master cylinder repair 5

[GGG7]

Hi everyone,Our team has been using AP Racing master cylinders CP7855-89 and CP7855-90 for a few years now. Recently, we discovered that they were bleeding, and after trying various fixes, we decided to open them up. Unfortunately, we found that the primary seal was ruptured/cut, and now it seems to have swollen, preventing it from fitting back into the cylinder bore.

We are based in Chennai, India, and are working on a tight budget with very limited resources. Our competition is less than a month away, and we need to complete our car within a week to start testing.We are in urgent need of an alternatives or a way to get them manufactured locally. Any suggestions or guidance on where to source compatible parts or find a reliable local manufacturer would be greatly appreciated.

Also can we use primary seal of any master cylinder of different company with same bore size? If yes can you suggest any 15mm and 15.8mm bore master cylinder whose primary seal we can replace with ours.

Thank you in advance for your help!

 

[BrianPetersen]

A google search finds that these parts are readily available.

https://raceandrally.com/cp7854-cp7855-repair-kits

Not worth trying to re-engineer. Bear in mind that the cost of substituting parts in a safety-critical system is not just one of money but also of risk, and at the price of this rebuild kit, it's a risk not worth taking.

Yeah, it's in the UK, and would have to get from there to where you are, but that is what expedited air-freight is for. Or maybe a search of the internet would find someone closer.

 

[MintJulep]

AP has distributors in Bangkok and Singapore.

https://apracing.com/find-a-dealer

 

[TugboatEng]

If your seals are swelling there is mineral oil in the system. Don't use mineral oil as brake fluid. All components in your system including hoses are sensitive to damage from exposure to mineral oil as they are made from EPDM rubber. You should examine all rubber components if you have found swollen seals in the master cylinder.

 

[GGG7]

We have tried contacting multiple distribuors but none of them will be able to ship us required parts within time for our competition. So that is why are trying to find alternative solutions.

 

[MintJulep]

Find a friendly local hydraulic repair shop that will let you search through their stock of rebuild kits until you find a matching seal.

 

[TugboatEng]

Remember, you must use EPDM rubber seals for brake systems. Buna seals typically found at hydraulic repair shops are not compatible with brake fluid.

 

[waross]

but that is what expedited air-freight is for.

Admittedly a different time and place but:
One airline at one time made a distinction between Air Freight and Air Express.
Air express went on the plane first.
Air Freight went on the plane "Space available".
How do I know?
I needed parts shipped across Canada immediately for a vessel scheduled to sail in a few days.
I discovered the difference between Express and Freight just after the parts had been ordered to be shipped "Air Freight".
We could not afford even one day delay, and we couldn't take a chance.
It took a lot of phoning but I was able to have the shipping order changed from Air Freight to Air Express while the parts were actually on the truck on the way to the airport.
The parts arrived on time via Air Express.
Yes, a different time and place, but with your time constraints it may be prudent to check shipping options rather than assume.

--------------------
Ohm's law
Not just a good idea;
It's the LAW!

 

[LittleInch]

Or send someone to pick them up, or find a friend or family member to bring them out.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[mfgenggear]

Op
Ups red labe or blue label , over night, one day air or two day. I am sure there are competitors with the same.
Stop cheaping out, and spend the money

 

[Tmoose]

Every now and then o-rings and seals swollen by brief contact with the wrong fluid have mostly recovered dimensionally when cleaned with mild detergent then isopropyl alcohol, dried and gently warmed over night.

the next time that happens to me I might try using an Air conditioning vacuum pump to subject the unhappy seal to very low pressure after cleaning.

As others said, if the wrong stuff was introduced into the system, all the seals may have had a similar major allergic reaction.