Brake travel

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Markuscurillious

Markuscurillious

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So I have a 1973 Plymouth scamp and I redid the whole front disc brakes lines to calipers and there is still a whole bunch a travel before the brakes engage and it seems the rear brakes lock up before front brakes fully stop and ideas???
 
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Are the front calipers mounted with the bleeder up ? At the highest point ?
 
^^^^
Air some times is hard to escape and takes gravity and pressure to get all the air out. Sometimes in your case 73 up the combo valve may be an issue. Doubtful if the rear are kicking in. Tap on the front calipers with a rubber mallet while bleeding sometimes helps or reverse bleed them.
 
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If the brake warning light is not on the centering you speak of should not be an issue.

Did you change the master cyl?

Of not is it a disc / drum or drum / drum
 
Photos....

If you are using a newer 73? Up system components the proportioning valve is part of the diverter valve.

If you really don't have a proportioning valve then there's your problem. Rear brakes only need about 10% of the pressure of the front.
 
Combo proportioning valve distribution block 69 Up (I thought it was 73 up but online says 69 up???)
Screenshot_20200403-211348.png


Distribution block only 68 down

Screenshot_20200403-211442.png
 
Stock discs I guess I’ll have to check on it I mean I do t think the breaks are supposed to operate like that are they?
 
Master cyl
Front calipers
Distribution block

For starters
 
  1. This how the 71/72 Or so down was done. They did not use the Newer combo valve. The older used a distribution safety valve and separate hold off/ “Texas”-proportioning valve.

56BC83A3-A2BA-4B23-9BEC-6563C9A0E606.jpeg
 
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The newer valve can be used on all, but line connections will require some re-bending.

edit.

If BB 67-69 and using a heat shield you must use the separate valves! The newer combo valve does not fit under the heat shield!

809CF245-DB5B-448D-ADF2-1959EF40339D.jpeg
 
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Start with the simple stuff. Adjust the rear brakes up until it is TOUGH to turn the wheels. Take a short drive around the block, apply and release the brakes several times, leaving several seconds, say, 15-30 sec if you can between brake applications. Then come back jack up the rear and recheck the rears, tighten them up some more if they have become easier. This is just for testing. See if the pedal "comes up." If not, or very little, you may still have air.

You may have a mismatch between cylinder size, caliper piston size, and master cyl. bore. A smaller master and larger cylinders makes the pedal travel more, but gives you more braking force. The opposite is true with bore sizes reversed

Does the pedal feel fairly hard? Judging that is a lot tougher with a booster
 
Photos man photos. What is so hard to get photos from people.

"Doctor I have a bump on my face what is it?" How the heck can the doctor diagnose the problem from just that description

If you really don't have a proportioning valve no amount of adjusting or bleeding will fix it.
 
Dana67Dart said:
Photos man photos. What is so hard to get photos from people.

"Doctor I have a bump on my face what is it?" How the heck can the doctor diagnose the problem from just that description

If you really don't have a proportioning valve no amount of adjusting or bleeding will fix it.
Click to expand...

Agree with the pics! Likely not their issue though, but it helps when they ask!
 
Well it’s hard I’m not doing ground up restore just fix the problems it’s hard to see past the frame the drive train and not get transmission oil all over you ik it’s just a pain ig this is why breaks are a pain I’m just pissed cause I worked so hard and it didn’t fix the problem
 
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