No air in the lines, but brakes still squishy

[4x4Dad]

Here are the details:
1. Dana 30 with disc brakes from a CJ7 with new pads and one new caliper (old one was corroded. The Jeep does not pull in either direction when I brake hard. Dana 44 with 11" drums out back. New shoes and cylinders on the rear).
2. Dual master cylinder for disc up front and drums out back.
3. Speed bleeders in the rear (the bleed screws that came with the axle were slightly larger than 3/8" hex, which annoyed me).
4. PV2 combination valve (proportioning valve and metering valve--the latter being the kind that has a hex head under a little black plastic cap) like this one here.
5. All new hard lines and rubber lines.
6. No fluid leaks--NONE.

I've ble the system at least a half dozen times, but my pedal is still squishy/soft. If I push on the pedal, it's soft, but if I pump it once maybe twice, it firms up.

I read in quite a few places that the combo valves send pressure to the rear first and then the front on a disc/drum, but if the drums aren't tight enough the front discs won't engaged. So I've got the drums adjusted so that there is slight pressure (perhaps too much).

I'm thinking it's the combo valve, which is a new thing to me. Maybe the metering valve needs my attention? No clue what to do about it, though. I've read that you maybe need a third guy to push the metering pin in, but mine won't allow that, so I don't know what to do here. Is the PV2 valve wrong for my setup? If not it, then what?

Help!

 

[Torxhead]

Sounds like you have a put together brake system that might not want to work that well as a system. Here is a brake shop located nearby that specializes in modified systems like in hot rods and such, you might want to go see them:ABS Power Brake, Inc.
Large tires and tall gears do not work well together unless well compensated for either.

 

[Lumpy Grits]

To add-When I need to replace a caliper. I replace them in pairs to keep the braking equal side to side.
Is the bled nipple on that new caliper at the top of the caliper.
I would also go to a 'pressure-bleed' and see what that does.
LG

 

[4x4Dad]

Yeah, the calipers are bleeder screw up.

It's going into the shop. I've crossed the time vs. money threshold and won't be bleeding them a sixth time.

 

[Lumpy Grits]

Yeah, the calipers are bleeder screw up.

It's going into the shop. I've crossed the time vs. money threshold and won't be bleeding them a sixth time.

Please post what you learn.
LG

 

[4x4Dad]

Please post what you learn.
LG

Will do. It seems like I should have a stock-ish CJ7 setup (which was my goal), but I'll be danged if it's behaving like one.

 

[Techlight]

Totally not helpful...but I'd say it's behaving exactly stock'ish ...hope you get it fixed up!

 

[Lumpy Grits]

YUP-AMC went the cheap on the CJ brakes with that 20 rear.
LG

 

[WireEd]

I had similar problem when I bought aftermarket calipers. They had both stamped wrong L and R. Took several trips to the Napa store to sort that out. Swapped and they were fine. I have also seen internal leakage of the master cyl cause same issue. Hard to troubleshoot off a bench. This can especially be a problem if it is reman.


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[Kane]

Did you bench bleed the master cylinder before you installed it? there is alot of air in the piston that will not come out with a regular bleed after it is put in.

 

[ksouthw80]

When I changed all the brake hard lines, you can't imagine all the bleeding that took place , then, everything firmed up. Pressure bleeding is probably the answer . And ,YES bench bleeding is a must!

 

[ksouthw80]

Oh, and i tried several proportioning valves with no change.... Anyway sounds too late, let us know what they did and what work they charged you for!

 

[Lumpy Grits]

Any updates?
LG

 

[007]

Did you use a proportioning valve tool when you bled? You have to actuate that valve to get proper bleeding.


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[4x4Dad]

My PV2 valve wouldn't work with the special tool. This was the kind with a hex nut around the metering valve pin. In order to bleed it there, I had to loosen the hex nut, but then whenever I did that and pressed the pedal and the metering pin, it leaked. No matter how much I farted around with that thing, the pedal never firmed up. Maybe it was a bad PV2 valve--or a bad mechanic futzing around with a perfectly good PV2 valve. After bleeding the brakes six times, I decided to try something else.

So now I've replaced the PV2 combination valve with the built in metering valve with a Wilwood universal proportioning valve (#260-11179). Doing so has gotten me a firmer--if not fully firm--pedal. I've also added residual pressure valves.

Now I just have to get the rear drums dialed in (having difficulty adjusting the shoes) so that I can use the proportioning dial/knob on the Wilwood valve to get them setup right, with them set to have enough pressure to not quite lock up when I slam on the brakes. I'm hoping this will be the end of the saga.

The other issue is that I t's also been a LONG time since I've driven a manual brakes vehicle, so I'm not quite sure how the pedal response is supposed to feel. (My other Jeep is a Grand Wagoneer with power EVERYTHING--not that all those power doodads still work).

 

[Lumpy Grits]

Manually adjust the rear 'shoes' till you just hear them drag on the drum.
Pump the b'pedal several times, and check again for the slightest amount of drag on the drum.
Do this to both drums.
LG

 

[Torxhead]

I would think using a brake pressure gauge would help with setting that Wilwood unit.

 

[jammer1]

My PV2 valve wouldn't work with the special tool. This was the kind with a hex nut around the metering valve pin. In order to bleed it there, I had to loosen the hex nut, but then whenever I did that and pressed the pedal and the metering pin, it leaked. No matter how much I farted around with that thing, the pedal never firmed up. Maybe it was a bad PV2 valve--or a bad mechanic futzing around with a perfectly good PV2 valve. After bleeding the brakes six times, I decided to try something else.

So now I've replaced the PV2 combination valve with the built in metering valve with a Wilwood universal proportioning valve (#260-11179). Doing so has gotten me a firmer--if not fully firm--pedal. I've also added residual pressure valves.

Now I just have to get the rear drums dialed in (having difficulty adjusting the shoes) so that I can use the proportioning dial/knob on the Wilwood valve to get them setup right, with them set to have enough pressure to not quite lock up when I slam on the brakes. I'm hoping this will be the end of the saga.

The other issue is that I t's also been a LONG time since I've driven a manual brakes vehicle, so I'm not quite sure how the pedal response is supposed to feel. (My other Jeep is a Grand Wagoneer with power EVERYTHING--not that all those power doodads still work).

I have a question for you. Will this valve work with the stock brake line fittings or will you have to get adapters to fit the line. I have stainless steel lines installed and they a very hard to try to cut the fittings off and flare new fittings on. Thanks.

 

[4x4Dad]

I have a question for you. Will this valve work with the stock brake line fittings or will you have to get adapters to fit the line. I have stainless steel lines installed and they a very hard to try to cut the fittings off and flare new fittings on. Thanks.

It took the standard 3/8-16 brake line nuts. Easy setup for me. I was actually able to remove some of the adapters I'd had to have to work with the PV2 valve.

 

[jammer1]

Sounds good thanks for the info. May have to go that route since the valve I put in 2 yrs ago is starting to leak again. Can't find good stock style valves.