| Author |
Message |
Mike Charness (Mcharness)
Intermediate Member
Username: Mcharness
Post Number: 1057
Registered: 8-2002
| | Posted on Monday, September 29, 2003 - 8:24 am: | |
Right -- always check for leaking brake cylinders. In fact, it's not a bad idea to change rebuild your brake cylinders when changing a leaky master, since the extra pressure might *cause* maginal wheel cylinders to start leaking. |
Ken A (Zff)
Junior Member
Username: Zff
Post Number: 146
Registered: 12-2002
| | Posted on Monday, September 29, 2003 - 6:04 am: | |
This is an update to help someone who may come across this thread in a future search.
I rebuilt the passenger-side rear caliper and my pedal sink problem seems to have gone away.
I guess that means that this problem - pedal sinking with light brake pressure - doesn't always mean an issue with the master cylinder.
Thanks everyone for your help. |
Ken A (Zff)
Junior Member
Username: Zff
Post Number: 140
Registered: 12-2002
| | Posted on Saturday, September 20, 2003 - 8:57 pm: | |
So it turns out it might not be my master cylinder after all.
I inspected the caliper at every corner and it looks like my other rear caliper - the one I didn't rebuild - is leaking, but only when applying the brakes lightly. Applying the brakes hard doesn't cause it to leak, and unlike the problem I had with the other rear caliper, it won't leak at all if you don't apply the brakes. |
1975GT4Don (1975gt4don)
Junior Member
Username: 1975gt4don
Post Number: 76
Registered: 1-2002
| | Posted on Tuesday, September 16, 2003 - 12:45 pm: | |
Superformance is a bit more, plus if you add shipping costs from the UK plus the VAT, it isn't too hard to figure out. Turn around time from whitepost is 2 days. Whitepost resleeves the master cyl with brass and lasts almost forever vs the OEM construction. |
Mike Charness (Mcharness)
Member
Username: Mcharness
Post Number: 990
Registered: 8-2002
| | Posted on Monday, September 15, 2003 - 5:13 pm: | |
That's about the same price as a new one from Superformance UK |
1975GT4Don (1975gt4don)
Junior Member
Username: 1975gt4don
Post Number: 75
Registered: 1-2002
| | Posted on Monday, September 15, 2003 - 3:27 pm: | |
Ken, you can have the master cyl rebuilt for $225 plus shipping, the work is guaranteed for the time you own the car. www.whitepost.com
check them out. |
Ken A (Zff)
Junior Member
Username: Zff
Post Number: 134
Registered: 12-2002
| | Posted on Sunday, September 14, 2003 - 10:49 pm: | |
Thanks for the help!
Ugh, Superformance is closed until Sept 25. |
Mike Charness (Mcharness)
Member
Username: Mcharness
Post Number: 988
Registered: 8-2002
| | Posted on Saturday, September 13, 2003 - 7:22 pm: | |
I bought my replacement master cyinder from Superformance for my 1984 308QV. It worked great. I considered rebuilding the master, but at the time they didn't have the rebuild kits, and my mechanic said that for the price, just replace the entire unit. He said that the only thing he had to do to it was to slightly enlarge the mounting holes as they were just a touch too small for "plug and play" replacement of my original. Otherwise, he said it was identical and perfect. And of course, it DID solve the "pedal creep" problem. I've kept the old one in case I ever decide to take it apart and/or do a rebuild. If you do, be VERY careful when you take off the c-clip, as I'm told that there are some strong springs in there.
While I had the brake system apart, I also had Goodridge stainless steel braided teflon brake lines put on, which added a "crisper" feel. Well worth it.
|
Ken A (Zff)
Junior Member
Username: Zff
Post Number: 133
Registered: 12-2002
| | Posted on Saturday, September 13, 2003 - 6:28 pm: | |
Hi everyone,
When I apply my brakes lightly, the pedal slowly sinks and pumping it will make the problem go away. When I apply strong pressure, the brakes work normally. I did some research here, and found this thread from a few months ago:
http://www.ferrarichat.com/discus/messages/256120/256829.html
It's pretty much the same symptom Mike Charness described as cup seals becoming less pliable and leaking fluid. I have a few questions regarding this.
Superformance sells the master cylinder for a 308, but they appear to specialize in Dinos. When they say "308" I assume they mean 308GT4. Would this matter? Does my '83 QV use the same part?
Most people seemed to favor a replacement rather than a rebuild. A few months ago, I rebuilt one of my rear calipers and rather enjoyed it. I think it would be interesting to rebuild the master. Is this a job difficult enough that I should not attempt it? I don't want to mess up my master... there's too much at risk if it doesn't work right.
Thanks |