I would like to ask this to the 92-95 Civic road racers and open trackers. Brake master cylinder failures, how often does it occur to you? For me, I seem to have my master cylinder start to fail after about 5 race weekends. This is true for Honda original parts and Kragen replacement parts.

 

5 race weekends? That's crazy. I replaced the one that came on the car when I bought it and it's been working fine ever since. I replaced the one on my old car a year before I wrecked it and it was also working fine. What are your symptoms and are you sure it's the M/C that's bad?

 

maybe ur preloading the master too much.
this thread tells how to check and adjust
https://honda-tech.com/zerothread?id=255804

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by johng &raquo;</TD></TR><TR><TD CLASS="quote">5 race weekends? That's crazy. </TD></TR></TABLE>

Something else has got to be happening. I replaced mine last year. It had approx. 69k street miles on it. When I rolled the original coupe, it got swapped into the current shell. 1/2 year (of additional) HPDE & the full enduro season except for the 12 Hour.

I have heard that how you bleed is important to the life expectancy of the MC. Apparently, if the pedal goes to the floor, it shortens the lifespan. Something about damage to the seals, which is how mine died. Not sure is this is BS or not.

 

This feels very much like a messageboard rumor to me.

The service manual says nothing about not going to the floor.

 

It's true. Don't push it to the floor when bleeding. Reason being is that crud tends to accumulate on the walls over time, especially in the section that the seals do not regularly pass over. If the seal is old, and the walls have crud on them, there is a slight chance that you could damage the seal as it passes over the unused section of the walls.

Just a risk that need not be taken, imo.

Warren

 

greg, dont you think it could be some other seal like in one of the calipers? how bad is it failing?

 

i have heard it is quite common on these cars. i've replaced mine twice. when i first bought it(160k) and last year (2 yr. span). i heard the same thing obout the crud. luckily they are cheap and easy to replace. keep the fluid clean.

 

I put a new MC 5 events ago. The brake pedal was becoming longer after every track session. I would adjust the star gear in the drums and bleed the brakes after every track session. Despite my efforts the pedal would not return to a solid and short push. I replaced the MC and the pads, the pedal was back to a solid and short feel. At the Feb N.A.S.A. HC, the pedal was OK. At the SCCA opener 2 weeks ago, I ran 5 sesions and by the 5th session, the pedal was really long. I am about to replace the MC again.

I did not think of the seals on the calipers, maybe, I'll replace that first. I looked at the calipers and there was not a sign of any leak. I'll look again.

Hopefully I can get this sorted out before the may 25th Feb N.A.S.A. HC race at Infineon.

Shoot away with the feedback guys.

 

From my limited experience its probably not the MC. Can you check to see if you have some caliper slop when you apply the brakes (just see if the caliper moves when you apply the brakes). We go from "heel-toe" to "ankle-toe" usually during the course of a race (best case during the course of a day). I don't think its unusual. My understanding of MC issues would show themselves if you apply pressure to the brake (car on) and the brake pedal starts to fall away from you (toward the floor). If its just elongated pedal travel, I'd hedge that its in the calipers/slide pins/tapered pads/shoes out of adjustment.

I think we have averaged a caliper rebuild about every 3 race weekend and/or caliper replacement every 6 or so weekends.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Warren &raquo;</TD></TR><TR><TD CLASS="quote">It's true. Don't push it to the floor when bleeding. Reason being is that crud tends to accumulate on the walls over time, especially in the section that the seals do not regularly pass over. If the seal is old, and the walls have crud on them, there is a slight chance that you could damage the seal as it passes over the unused section of the walls.

Warren</TD></TR></TABLE>

Tis true.

 

I still have the original MC in my 94 Civic EX. The car now has 6900ish miles on it. (All race miles from new) I purchased a 'backup' MC and carry it with me incase I have issues. When I bleed the brakes, my pedal goes all the way to the floor - every time... I've heard the same concerns about the MC failing, and I bought the spare. As of a few weekends ago, my brakes still feel 100%. Maybe I'm just lucky!