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**DONOTDELETE** 09-10-2001 01:42 PM

bad master cyl or just need bleeding?
I called a shop to ask about bleeding my brakes because they're mushy. The guy said that the only reason they would be mushy is because of air and since it doesn't seem to be leaking any fluid it is probably the master cylinder. This sounds a bit suspicious to me. I understand what he's saying but can't air get in there other ways? Thoughts?


JEEPN 09-10-2001 02:02 PM

Re: bad master cyl or just need bleeding?
Yes, it is possible. I have seen it happen before, when the lines start to wear out or rust near the joints, air gets in there, and then when you press on the pedal, it moves the line slightly and seals it. This is highly uncommon, and I have only seen it happen once, and we did notice it by the wet area around the threads. I have also heard of it happening with the copper washer, but this is usually on installation and it's highly irregular.

I'd bleed them yourself by gravity, we just discussed how on this BBS, try a search as well. If you still want them to bleed them, just let them know and they'll do it, but be prepared to shell out some more $$$ if the master is toast.

Winter Harbor, Maine
'81 CJ-8 Scrambled, It's a Jeep, Chevy, IHC kinda thing!
'88.5 Zuki, 7" Lift, Locked, Swamped, Rolled, and just generally broken in right!

wades_76_CJ7 09-10-2001 02:07 PM

Re: bad master cyl or just need bleeding?
Have you replaced any brake components? ie. calipers, wheel cylinders. did you put braided lines on or anything?

I just replaced my master cylinder on mine. They were mushy, but they also had a little air in one line. I couldn't get the bleeder loose on one wheel cylinder.
The reason i replaced the M/C was that it had finally went south. the brakes would release slowly while sitting at stoplights and such. It would work if i pumped them, but a rebuilt one was only $18.

Replacing the M/C was easy. You can do it.the hardest part is getting the old fittings out of the M/C w/o kinking the lines. I would strongly recommend a couple of days before you start, spray some Liquid Wrench or the like on all the bolts and the brake fittings.

76 CJ7, 258,Jeep T18, D20 TC, D30 & AMC20.
4" Superlift, 33" SSR's

**DONOTDELETE** 09-10-2001 02:17 PM

Re: bad master cyl or just need bleeding?
Just to add on - you can get rebuild kits too. And to make one man brake bleeding forever easier, I just saw some check valve style bleeder screws in a magazine. Much faster than gravity and much simpler than using the vacuum pump.

Tread lightly and stop to smell the roses - Traveler

GP'n 09-10-2001 03:27 PM

Re: bad master cyl or just need bleeding?
Little foot
I would be very interested to know more about these valves. could you tell me where you saw them. maybe an address or number to contact them, Thanks

**DONOTDELETE** 09-11-2001 12:46 AM

Re: bad master cyl or just need bleeding?
remember to bleed them starting at the longest line and working towards the shortest line.

The bleeder nuts that attach to each wheel cylinder run about 7 bucks apiece (I think).

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