Cleaning a Volvo 850 master cylinder?

Question

Has anyone taken apart or fixed a master cylider on a 1993 volvo or any master cylinder for that matter and been able to clean it and put it back together or does it just need to replaced?

Answer 1

Ryan,your Volvo is 13~14 yrs old.

You would not want to simply take it apart,,clean it,then reassemble with same parts.

All the elastomers need to be changed,,cups,seals ,etc.

None of which is any big deal,,,very simple and straighforward repair.

The CATCH is,,,,it's almost impossible to find repair kit parts for Anything with ABS.

I'd LOVE you to prove me Wrong,,,cuz it would save you $100~200 to be able to rebuild it yourself....
But I SERIOUSLY doubt you'll be able to find the necessary parts.

the LAST thing you want to do is dismantle it,,,,let the rubber goods hit air for a while,,,,then re-assemble with the OLD parts.

Dont even think about that.
Especially not at that age.


If You're In the USA,,,Autozone often has best prices on Volvo Parts.

Pays to shop around,,,prices vary WILDLY on rebuilt master cylinders.
Depends on how much Guts/Conscience the Rebuild Vendor has in pricing his minimum wage labour spending 10 minutes to install $5 worth of parts.

Some come WITH the fluid reservoir,,,and are more expensive,,
some come without & you re-use you old reservoir---these are usually cheapest.

My OPINION......on a car that age,,I'd get one with a new reservoir,,all ready to bolt on.
I beleive the extra $$ is well spent


Hope that helps,,Good Luck with it

Answer 2

Ryan, It's a job for a professional because the technician can recognize what work needs to be done and they have the precise tools to do it. If the interior of the cylinder needs reconditioning they have the stones and hones to bring it back into specification. Don't risk your neck by trying to do this job yourself. The master cylinder is the only source of pressure for your entire breaking system. The pros no how to pre-clean and final clean before reassembling. The grooves, O rings and seals must seat perfectly. If its in bad shape they'll tell you to get a recon unit to replace the original. While your at it have your brake fluid replaced. Slick new equipment does a perfect job. Old fluid contains water and that alone may have caused the master cylinder to fail

Answer 3

You can do this quite easily witha bench vise,,,clamp it with the resevoir side up, and the push rod end toward you, in the vise.
Remove the circlip at the rear of the cylinder.
Then remove the pistons and seal's,,,,(if you have an air chuck you should be able to do this by applying air) when you have the pistons and seals removed,,,clean the inside of the cylinder bore,,,and take a light,,and look into the cylinder bore,,,,you want to see a nice bright,,,non rusted or pitted surface.
If you see small dark pock marks,,,or rust.
Then you need a new master cylinder.
If the bore is still clean and bright,,then you can take your rebuild kit and change over the seals and or piston's sets.
and re-assemble.
Keep everything clean,,and tidy,,and you shouldnt have a problem.

Answer 4

i exploit a suction gun to get rid of the fluid from the res. top off with new fluid, open front bleeders on calipers and permit drip till sparkling fluid seems. visit rear and positioned a hand vacuum brake bleeder and suck the hot fluid in the process the traces.