Power Brakes...

Midnight Special · Jan 23, 2007

...All of a sudden this a.m., I noticed my brake pedal slowly going all the way to the floor. I pulled into a gas station & could find no fluid loss, no vacuum noises , plus the wheel cylinders are all new... The car will stop, tho you must pump it a few times to keep pressure, especially when at a stoplight. Does this sound like a possible "master cylinder" problem?

Thank you in advance for your thoughts.

rvrtrash · Jan 23, 2007

If everything is as you say, I'd guess the seals inside the bore of the master cylinder are letting pressure off. Has the master cyl been rebuilt? If it has, you may have to go to an oversize seal kit. A lot of times people or shops will hone the bore, get carried away and hone too much, and then use standard seals. If it hasn't been rebuilt, it probably just needs a kit. They're fairly easy to install. Get with me offline and I'll talk you through it if you want.

Steve

P.S. I'm assuming you did a good bleed when you changed the wheel cylinders and don't have air in the line, which will give much the same symptoms.

Midnight Special · Jan 23, 2007

Thank you Steve!

All of the brakes, wheel cyls. and two of the lines were done at a shop about 2 months ago. The master cyl. was not... Everything has worked perfect (all driving styles) from then until now. I also noticed that when I pump it up real hard while stopped - it will stay "charged" for awhile before it bleeds off. But it's intermittent & not consistant...

What you said makes good sense Steve! I will investigate further & get a kit.

Thank you

rvrtrash · Jan 23, 2007

Any time!

Steve

Midnight Special · Jan 25, 2007

Follow up...

rvrtrash said:
If everything is as you say, I'd guess the seals inside the bore of the master cylinder are letting pressure off. Has the master cyl been rebuilt? If it has, you may have to go to an oversize seal kit. A lot of times people or shops will hone the bore, get carried away and hone too much, and then use standard seals. If it hasn't been rebuilt, it probably just needs a kit. They're fairly easy to install. Get with me offline and I'll talk you through it if you want.

Steve

P.S. I'm assuming you did a good bleed when you changed the wheel cylinders and don't have air in the line, which will give much the same symptoms.

...Went to get a kit, but for only $11.00 more, got a whole replacement unit.
I removed the old one (will save fror rebuild), bench bled the new one, installed and bled all lines. She now works perfect!!!

Thanks again Steve

rvrtrash · Jan 25, 2007

You mean I got it right? Dang, how did that happen?:grin:

Steve

Midnight Special · Jan 25, 2007

rvrtrash said:
You mean I got it right? Dang, how did that happen?:grin:

Steve

...I donno Steve, but safe to say now you can probably "stand behind" your advice on brake jobs! That is... If I goofed somewhere - I wouldn't want you standing in front of it ;-))

PFSlim · Jan 26, 2007

Good Job STEVE!!! He is so helpful!! Got to say that he has helped alot of us in the field of electrics and brakes.

Paul

joedls · Jan 26, 2007

Steve's "THE MAN"!!!

rvrtrash · Jan 28, 2007

:embarass: :embarass: :embarass:

Thanks guys! I was gone for a few days and missed my moment in the sun. I do wish to state that I feel the little bit I'm able to contribute here is only a small portion of what I receive.

Steve

Power Brakes...

Midnight Special

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Midnight Special

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Midnight Special

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