cj7 master cylinder

[juggernaught]

I would think that power bleeding would not require you to remove the calipers. But, If I have to manually bleed the brakes that is something I will keep in mind. I think my bleed ports are mounted rather low.

[Old Rugged Crosser]

I am familiar with the hydroboost system and don't want to go there yet.unit?

The hydroboost system will not overcome the problem you are having. I am using a hydroboost system and also had to overcome the problem you are having.

NPD was right. You may have to remove the calipers to get out all the air. It is a air problem that you are having.

[Mudrat]

Any suggestions?

1. are you running bigger tires? If so how big
2. do you have a vacuum booster? If so have you tested it? The buggers tend to leak after a while.

Try the bleeding option first - cheapest of the lot obviously, but didn't overcome my stopping issue (35's). I had pedal pressure, just not enough grip to slow me as quick as I liked.
Disk rear's helped a lot after that. SSBC and TSM both have good $y$tem$ (and I have a set of TSMs for a stock D-20 rear up for grabs swapped in a D-44, with disks )

You don't want a longer throw on the pedal, you want a larger diameter piston - creates more PSI in the hose. If your not ready for Hydroboost, check into a corvett MC with a 1-1/8" bore, or a dual diaphragm vac booster. BUT, you need to be sure it's not trapped air first.

[juggernaught]

Thanks.............thats what I needed. Any idea what years of the corvette m/c will work? No vacuum booster so thats out.

Is it really necessary to hold the pin open on the proportioning valve either while hand bleeding OR power bleeding? The books say yes and the mechanics say no. Personally, I have never bothered with the pro/valve while bleeding my other vehicles.

Somewhere in the future rear disc brakes would be nice.

[tufcj]

No power brakes? Maybe that's the first upgrade you should think about. My 77 CJ was a factory disc/drum with power brakes. I'm still running the factory master cylinder with Wagoneer front calipers (dana 44), rear disc, and 37" tires. It stops like it did with the factory 29" tires.

Bob
tufcj

[Old Rugged Crosser]

Yes it is important to hold open the pin on the proportioning valve. Here is another tip.

Disconnect the two brake lines that go into the master cylinder and fashion two more lines that will screw into the M/C and turn them up and into the two M/C reservoirs then pump the brakes slowly and do not go all the way down on the pedal. keep stroking like this until no more bubbles come. Then connect the original lines. You should see a lot of difference.

[juggernaught]

Tufcj...........I just don't have a vacuum booster (nothing between the m/c and the fire wall).

[juggernaught]

ORC.......If I have someone power bleed my system, do they still need to open the proportioning valve? So far you are the only person telling me (besides the book) that it is mandatory to open the p-valve while bleeding.

I have made an appt. to have them power bled on Thur. morning along with checking the rear drums. I did not ask this guy about the p-valve.

This is one of those issues that has plagued me for a couple years. I would like to put it to rest. I somehow doubt that I am the only one with this issue. But I am very thankful for all the solid advice.

[tufcj]

The vacuum booster (the canister between the firewall and M/C) is what makes "power brakes". the vacuum booster assists you in applying the brakes, without it, it's entirely pedal pressure with your leg.

I agree that the rear drums being out of adjustment could cause a low pedal that will pump up.

Have you checked that the correct lines are connected to the right place on the M/C? Generally in a disc/drum setup, the larger reservoir is the front brakes.

Bob
tufcj

[Old Rugged Crosser]

Yes it is important to hold open the pin on the proportioning valve. Here is another tip.

Disconnect the two brake lines that go into the master cylinder and fashion two more lines that will screw into the M/C and turn them up and into the two M/C reservoirs then pump the brakes slowly and do not go all the way down on the pedal. keep stroking like this until no more bubbles come. Then connect the original lines. You should see a lot of difference.

Are you ruling this out? I wouldn't if I were you.