Brake problem pulls left hard

[knever3]

My '87 Comanche pulls hard and I can lock up the LF tire when braking. I have a '96 brake booster and master cylinder installed, rear load sensing valve deleted. I have attached a picture of my setup and from my research it's correct. This summer my right front caliper locked up smoking when I got home. I changed the caliper and it still pulls to the left.

 

Tonight I disconnected the hard line from the soft and to my surprise no brake fluid came dripping out! I inspected the flare and put it back together. I used my Motive pressure bleeder and pressured up the MC with fluid. I bled both left and right front wheels adjusted the rear adjusters just for kicks. Took it for a drive and it pulled hard left till it locked up the LF.

 

The soft lines and hard lines are all new, well 10 years old new. Thoughts? Bad soft line? Bad proportioning valve? I can't drive this in the snow this way!

 

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[ghetdjc320]

Sounds like maybe some debris in one of the prop valve passages. Was there any notable flow restriction once you bled out the front lines? Is the RF braking at all? 

[knever3]

Didn't seem to be a difference when I bled them. I haven't tried jacking it up and spinning the tire then braking. I know that usually when you remove a brake line it gravity drips and it i left it for 5 minutes and no fluid came out.

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[Eagle]

You don't have a proportioning valve -- you wrote that you deleted it.

 

Sounds to me like a bad caliper.

 

[ghetdjc320]

That’s a good point. Are you running just the stock distribution block then? If so, you may have some blockage there as those passages get mighty small. 

[knever3]

Yes, stock distribution block. I guess I thought the front block was considered a proportioning valve as well. The rear I would call a load sensing valve. My bad. I guess I could pull the caliper off and work the brakes to see if it moves. I don't know if the hose is bad or block.

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[ghetdjc320]

8 hours ago, knever3 said:

Yes, stock distribution block. I guess I thought the front block was considered a proportioning valve as well. The rear I would call a load sensing valve. My bad. I guess I could pull the caliper off and work the brakes to see if it moves. I don't know if the hose is bad or block.

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Much more likely the block. There are some pictures floating around in here if the block cut in half to show the passages and they are super small. They could easily get clogged.

[knever3]

So replace or use brake clean?

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[Eagle]

Photo of the distribution block:

 

 

The XJ/ZJ block is also a proportioning valve. The MJ is not. They look similar on the outside but the internals are different.

 

[cruiser54]

You want some good brakes?

$#!&can the distro valve. It's restrictive.

Run the line for the front brakes to a Tee that feeds both front brakes.

Run a line for the rear from the master cylinder and put an adjustable valve in it.