Any brakes lites in the dash on?

Rears only do 20 to 30 percent of the braking in any event...... so, they aren't going to get as hot as the fronts. Jack up the rears, (jackstands would be good.....) start it up, put it in gear, let the tires start rolling, and step on the brakes..... do the rears stop? If they do, give it a bit of gas while holding the brake, does it still hold?

Is your pedal spongy? Gotta push it a long ways before anything starts happening? (stops happening? something.....)

 

HeyYou;
Thank you for your reply. There are no lights coming on. there are no fault codes coming up. The truck just refuses to stop. The fronts will lock up on stones but the back wheels keeps rolling, even on stones. I will try the "jack up" tomorrow and see what happens. The pedal is solid, not spongy at all. I also unplugged the valve and test drove it to see if there was a difference. There was none and still no lights came on(applied brakes @ 50mph). They do come on and go off after starting the truck.(normal) I am at witts end LOL. Thank you so much for your reply and will let you know what happens when I jack it up. Thanks again.

 

Hi All;
Well I put it up on jackstands as advised and gave it some gas. Tires didn"t spin until I gave it quite a bit of gas. So anyway, I decided to do away with the WRAL altogether. I rerouted the brake line and removed the valve.On the road test, it appears to be about 50% better,but still not what it should be.Still will not lockup on stones. Anyway no fault lites or anything and everything else still works,ie...cruise, etc. I was wondering if anyone knows if there is an more aggressive rear brakeshoe made that has more binding ability. Seems like that would help if there was such a critter. Seem to be making some progress, but think the brake system on these trucks leave some to be desired.Thanks all

 

I know what people say about replacing the rear cylinders but I've also heard that the bigger cylinder takes more fluid and if you're still pushing the same amount with the master cylinder it will actually be worse. So, it would be more like replacing the master cylinder with one with a larger bore (I believe). I have not heard of other shoes to use in the rear. I do know that if you put them on backwards they stop much quicker. Normally the smaller shoe is the e-brake but when on backwards it becomes the normal braking shoe. Since it is smaller it puts more force on the drum. You could also put a rear disc brake kit on but they are pricey. You may also have a problem with the distro valve up front which is not allowing the rear to get enough pressure.

 

The smaller shoe is installed to the front, as they are 'self-energizing', which translates to..... When the shoe contacts the drum, friction from the drum actually draws the shoe into it, so it is much more effective than the rear shoe. Installing the shoes backwards certainly does make the brakes more effective, but, the front shoe will wear much faster than the rear as well.

Changing out the slave cylinders will give you better performance, so long as you keep your rear's adjusted up properly. Yes, it takes a bit more fluid, but, WHY it works is because you have a larger area available for the fluid to apply force to. So, for the same amount of brake 'pressure' you get more stopping force. Larger Master cylinder will enable you to move a larger VOLUME of fluid, but, it will still pretty much be at the same pressure. Of course, you are apply force over a larger area as well.... so, pressures might indeed be higher too. Might have to play with that, and test a theory.

You can also get shoes in different compounds.... I think. I know you can for the front.... Might wanna ask at your friendly neighborhood parts store. Keep in mind, you pay a premium price for premium pads/shoes..... but, I think the REALLY good shoes for my truck ended up costing me about 25 bucks......

 

Thanks alot guys. I think I will try changing out the proportioning valve and see if that makes a difference being thats the only thing left that hasn't been replaced. Appreciate the help and will keep you posted. Thank you

 

Hello again all;

Well I changed out the proportioning valve and it made quite alot of difference. Braking has improved quite a bit. Unfortunately I now have a new problem. When on blacktop road and slam on the brakes @ about 45 mph, the left front wheel locks up. I am really standing on them. Of course it is pulling to the left when I do it. I thought maybe I had air in the line, so I bled the complete system 3 more times,but did not stop the problem. I am not sure which wheel is the problem one. I know that sounds strange, but as hard as I am stepping on the brakes, you would think the one locking up is the one working right,but I am not sure of this. Is it possible the r/f is the one working properly and the l/f is locking up in error to make the problem? I checked to see if there was oil or some other debris on the rotors,but both are clean. As I said before,all were changed and new not too long ago. Included brakes,calipers,and rotors. I would sure appreciate any suggestions on this. Which wheel should I concentrate on? Thank you so much....spoc.

 

Try bleeding them again. Grab a warm body, stick said warm body in truck. Have warm body pump the brake pedal three times, and then HOLD pressure on it. Crack open a bleeder valve. Do that several times for each wheel, in the standard pattern. See if you get any more air out.

Something else to consider..... A locked brake is NOT slowing you down as quickly as a rolling tire (with brakes applied) would. Try going out, run your truck up to speed, and apply your brakes as hard as you can WITHOUT looking a wheel. (front anyway....) In a panic stop, you do NOT want to lock your breaks.

 

OK, I will do that again. Which front wheel do you think is acting up though, the locking one or the other? If they both locked up or both didn't,i would imagine everything was ok. So if re-bleeding makes no difference,which wheel would I scrutinize? I cannot do it until it stops raining,but just in case,looking for my next step. As usual thank you very much

 

I went out and re bled the system as advised and then did it again just to be sure. I then took it down the road and everything was exactly the same. The left front locked up. I then took it up to 50 mph and applied brakes as to try not to lock it up. you could feel the truck pulling to the left the harder I pushed on the pedal. I don't think in an emergency situation I would push the brakes carefully as to not lock up that wheel. Anyway thank you and back to the drawing board. Thanks again...spoc.

PS I have used over a quart of fluid so far in the bleeding process and at last bleed,didn't find any air in the lines.(just so ya know)