TheSamba.com :: View topic - Do i need to grease a new master cylinder? success!

Thu Dec 08, 2011 4:58 pm

Just bought a brax master from cip1 and it came with a paper that explains I need to use "correct smearing", disassemble the cylinder, clean it with alcohol, and apply a thin later of ATE grease on stamp and rubber gasket. I do not know what this means.

Thu Dec 08, 2011 5:02 pm

Not sure either, but don't put grease anywhere near the M/C. :shock:

Maybe on the end of the pushrod. 8)

Thu Dec 08, 2011 5:04 pm

Had me a girlfriend that demanded correct smearing,miss that freak,even after all these years..

Fri Dec 09, 2011 11:29 am

Once upon a time VW did have "Brake cylinder Paste" that was to be used when building or rebuilding a brake cylinder. The paste helped to lubricate the seals inside.

Found silicon grease at NAPA for this and have been using it for a while.

Also good to add a dab of never seize to the threads on the brake lines and bleeder valves to help keep them from rusting up. Do use the rubber caps over the bleeder valves or those will rust up!!

Work the brake line nuts back a bit on the metal lines and put a little NS or grease on the line where the nut will surround it. That will keep the inside of the nuts from rusting to the metal brake lines.

Fri Dec 09, 2011 11:33 am

Image below from the "Look, Listen, Do It Better" VW dealer training booklets, which can be accessed through the "Technical" button at upper right of this web page.

Fri Dec 09, 2011 12:59 pm

Eric&Barb wrote: Once upon a time VW did have "Brake cylinder Paste" that was to be used when building or rebuilding a brake cylinder. The paste helped to lubricate the seals inside.
Wurth makes a brake assembly grease that i use when rebuilding calipers and cylinders. it's made specifically for use in brake hydraulic parts assembly.

Fri Dec 09, 2011 10:27 pm

ahh thanks for all the responses guys, including the hilarious johnnypan. It sounds like it is a more common thing when rebuilding a cylinder, but is it truly necessary i take apart a brand new one to put grease in it?

Fri Dec 09, 2011 11:30 pm

Frankus12 wrote: ahh thanks for all the responses guys, including the hilarious johnnypan. It sounds like it is a more common thing when rebuilding a cylinder, but is it truly necessary i take apart a brand new one to put grease in it?

I never have, and never had a failure either.

Sat Dec 10, 2011 12:52 am

69 Jim wrote: Frankus12 wrote: ahh thanks for all the responses guys, including the hilarious johnnypan. It sounds like it is a more common thing when rebuilding a cylinder, but is it truly necessary i take apart a brand new one to put grease in it?

I never have, and never had a failure either.

I never have taken apart a new one either, and mine all have worked for decades.

Sat Dec 10, 2011 7:07 am

The answer is NO,the odds of screwing something up is way higher than the gains...dont use neversieze on threads or tubes or flare nuts,lubricants on rubber,NEVER introduce any chemical compound that could contaminate the brake fluid..

If you install the cylinder correctly there is no reason ever to take it apart again except to replace it...in another twenty years...

Sat Dec 10, 2011 8:55 am

johnnypan wrote: The answer is NO,the odds of screwing something up is way higher than the gains...dont use neversieze on threads or tubes or flare nuts,lubricants on rubber,NEVER introduce any chemical compound that could contaminate the brake fluid..

If you install the cylinder correctly there is no reason ever to take it apart again except to replace it...in another twenty years...

I missed that earlier. I agree adding any chemical to the system that is not brake fluid is wrong. Anti-seize is not necessary. If a fitting is rusted that bad after 20 years, just replace it.

Sat Dec 10, 2011 11:02 am

okay! thanks a lot all im going to go ahead and install the cylinder today. Ill Let you know if it fixes my problem of low pedal and weak action.

Sat Dec 10, 2011 11:07 am

adjust the brake shoes also :wink:

Sat Dec 10, 2011 11:14 pm

well the cylinder is in, and all hooked up. I did not bench bleed because i do not have the tools and plenty of people have said its not necessary, just ideal. of course im probably paying the consequences now, the pedal goes to the floor after 30 min of gravity bleed and some pump bleeding. I will resume bleeding and adjusting the shoes tomorrow and let yall know what happens. O yea, and just curious, would undoing the pressure lines from the m.c. and letting fluid run through gravity bleed the cylinder? or does that just let air in?

Sun Dec 11, 2011 12:10 am

Frankus12 wrote: well the cylinder is in, and all hooked up. I did not bench bleed because i do not have the tools and plenty of people have said its not necessary, just ideal. of course im probably paying the consequences now, the pedal goes to the floor after 30 min of gravity bleed and some pump bleeding. I will resume bleeding and adjusting the shoes tomorrow and let yall know what happens. O yea, and just curious, would undoing the pressure lines from the m.c. and letting fluid run through gravity bleed the cylinder? or does that just let air in?

Open thr bleeders, not the lines. :wink:

Sun Dec 11, 2011 9:50 am

johnnypan wrote: The answer is NO,the odds of screwing something up is way higher than the gains...dont use neversieze on threads or tubes or flare nuts,lubricants on rubber,NEVER introduce any chemical compound that could contaminate the brake fluid..

If you install the cylinder correctly there is no reason ever to take it apart again except to replace it...in another twenty years...

Yes one does not want that inside the brake system, but as directed before one is applying it outside the system. The brake lines do not use the those areas to seal, plus no rubber in those areas and not inside the system. Very end tips of the brake lines are the sealing areas.

Sun Dec 11, 2011 5:32 pm

well, the report is in. Same brake pedal position as before, all shoes are tight as hell except one in the rear because the star is stuck, but its still pretty close. Bleeding was not 100% thorough, i was still getting popping out of the rear left bleeder when my partner was pumping the pedal. we worked on that wheel for a good 10 min and still was popping. Idk what to do, maybe just take it somewhere and have them tell me whats wrong lol. im tired of brake fluid on my skin!

Sun Dec 11, 2011 6:12 pm

Frankus12 wrote: well, the report is in. Same brake pedal position as before, all shoes are tight as hell except one in the rear because the star is stuck, but its still pretty close. Bleeding was not 100% thorough, i was still getting popping out of the rear left bleeder when my partner was pumping the pedal. we worked on that wheel for a good 10 min and still was popping. Idk what to do, maybe just take it somewhere and have them tell me whats wrong lol. im tired of brake fluid on my skin!

try gravity bleeding...start at the furthest wheel from the master cylinder,crack the bleeder and wait...no pumping...when a steady trickle comes out for a bit go to the next wheel furthest and repeat till ya do all four.

Sun Dec 11, 2011 6:36 pm

Quote: try gravity bleeding...start at the furthest wheel from the master cylinder,crack the bleeder and wait...no pumping...when a steady trickle comes out for a bit go to the next wheel furthest and repeat till ya do all four.

Okay, i will try it again, but i have my doubts. if i may, I would like to take this back to a stand point of status: all brake parts are very old, except new lines and mc. when i got the car, the system was dry. braking was weak and the pedal went low, but never did it drift down as if there was a leak. no leak+good shoe adjust=bad mc. well with the new mc it seems just like before., but it does this funny thing where if i get on the brakes slow, it will go pretty far down, and if i get on 'em fast, it wont go as far i.e. it feels better. pedal is a little squishy, if i go from normal braking to hard braking it will move about an inch. pushrod is adjust good when measured with freeplay at pedal. im stumped

Sun Dec 11, 2011 6:42 pm

Make sure the bleeder is closed while the pedal is being pumped. after a few pumps, hold the pedal down while you open the bleeder. Make sure the bleeder is closed before the brake is released, or you will allow air back in the lines.