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72 Brake System Question # 2

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heapum

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This question is still a part of the original entry about my CK-10 brake system that will not stop my truck like any other normal system. I basically have to stand on the brake pedel with both feet to stop quickly and still it takes twice as long.
I noticed that someone said that the rear reservoir always feeds the front brakes and I thought I should look at mine to see and sure enough I have a small & large reservoir on my M.Cyledar, but the rear (the closest to the fire wall) reservoir is the larger of the two and has a larger line that goes to the rear brakes via the proportioning valve with the smaller of the reservoirs having the smaller line that goes to the front disk.
After driving this 15 years without having adiquate brakes and spending a fortune on mechanics, m.cylendar/boosters this seems like this would be too obvious a problem to over look??? Any advice would be greatly appreciated.
Thx,
Heapum
 
I too had many years of bad braking, I swaped out the booster, master cylinder 3 times, calipers and everthing eldse I could think of. The only time I ever saw improvement was when I finally swapped out the proportioning valve for a manually adjustable one and most importantly changed the flexable brake lines for stainless steel braided ones. I wish I had done this eyears earlier, it made a huge difference!


Hope this helps!
 
>This question is still a part of the original entry about my
>CK-10 brake system that will not stop my truck like any
>other normal system. I basically have to stand on the brake
>pedel with both feet to stop quickly and still it takes
>twice as long.
>I noticed that someone said that the rear reservoir always
>feeds the front brakes and I thought I should look at mine
>to see and sure enough I have a small & large reservoir on
>my M.Cyledar, but the rear (the closest to the fire wall)
>reservoir is the larger of the two and has a larger line
>that goes to the rear brakes via the proportioning valve
>with the smaller of the reservoirs having the smaller line
>that goes to the front disk.
>After driving this 15 years without having adiquate brakes
>and spending a fortune on mechanics, m.cylendar/boosters
>this seems like this would be too obvious a problem to over
>look??? Any advice would be greatly appreciated.
>Thx,
>Heapum



HELLO,

A COUPLE OF QUICK QUESTIONS.
1. DOES THE TRUCK PULL TO EITHER SIDE WHEN THE BRAKES ARE APPLIED?
2. IS THE PEDAL HARD TO PUSH?

I THINK I CAN HELP.

BRANT
 
Hello Brant,
No, the truck doesn't pull to either side.
Yes, the brake pedel is hard to push, but not as hard as if the booster was bad because the booster checks out good.
The proportioning valve check out good as well.

Thx,
Heapum
 
Hello Sean,
Thanks for your reply. I do plan on changing out the brake lines at the front wheels and the single line in the rear, but since this is a 4WD I am not finding a supplier for those stainless steel lines that you have suggested.
The manuel propotiong valve is a new idea that I will have to look into since I am not sure what that is all about.
Thx,
Heapum
 
HELLO AGAIN,

THE ADJUSTIBLE PROPORTIONING VALVE IS A GREAT IDEA, ASSUMING THE MASTER BOOSTER COMBONATION ARE CORRECT. REPLACING ONE WITHOUT REPLACING THE OTHER AT THE SAME TIME IS NOT A GOOD IDEA. ESPECIALLY IF THEY ARE NOT A MATCHED PAIR. THERE ARE SEVERAL DIFFERENT STROKE LENGTHS FOR BOTH THE BOOSTER AND THE MASTER. REPLACING THE MASTER FROM ONE MANUFACTURER AND THE BOOSTER FROM ANOTHER CAN CAUSE HEADACHES.
BACK TO ASSUMING THEY ARE CORRECTLY MATHCED, I HAVE MORE QUESTIONS.
1. HAVE YOU BLED YOUR WHEEL CYLINDERS AND CALIPERS YOUR SELF, OR DID A SHOP DO IT?
2. IF YOU DID IT, DID THE FLUID SHOOT OUT AS IF UNDER LOTS OF PRESSURE INSTEAD OF POURING OUT?
3. DO ANY OF THE WHEELS LOCK UP?
4. DO ANY OF THE WHEELS SEEN TO DRAG EVER?
5. DID THE TRUCK EVER STOP PROPERLY SINCE YOU'VE OWNED IT?
6. ARE THE AXLES ORIGINAL FOR THAT YEAR, MODEL?

I'M SURE I CAN HELP YOU.

BRANT
 
I was also unable to find a supplier for my brake lines. I auctually had purchased ones made by Explorer- Pro Comp but the fitting were the wrong size. I went down to my local speed shop and bought the parts to assemble them myself.

If you send me an email ([email protected]) I can send you a pic of the lines I made as well as the way I set up the manual proportioning valve.

A note about this valve; the line going to the front wheels will come straight from the master cylinder, the line to the rear wheels goes through this valve and can be adjusted to lessen the pressure.

before installing the manual valve the rear brakes would always lock up before the front on hard braking and cause the rear end to fish tail around (a very scary situation). Now that I can manually adjust the brakes, after some testing it stops without the fishtail, and probably knocked at least 20 feet of my stopping distance.

The valve I got was from summit, I think it was made by wilwood.
 
Hello Brant,
I will try to answwer your questions and keep it short.
I am suspecting more and more that I have had miss matched parts on this truck from the begining, but am gathering as much info. as possible before tearing into it this fall.

1. Wheel cylendars have been bleed many times in many different shops, but I am not sure about the pressure.
2. See #1
3. My wheels have never locked up unless I am pushing on the pedel with both feet and even then it is delayed somewhat.
4. Wheels have never dragged to my knowledge.
5. This truck has never had good braking / stopping power.
6. Yes.

Any ideas will be appreciated.
Thanks,
Heapum
 
HELLO AND THANKS FOR ANSWERING MY MANY QUESTIONS.
DISC/DRUM SYSTEMS LIKE YOURS AND MINE REQUIRE THE LARGER RESERVOIR IN THE MASTER TO OPPERATE THE FRONT/DISCS. REASON BEING, THE CALIPERS HOLD MUCH MORE FLUID THAN THE SMALLER WHEEL CYLINDERS AND SINCE THEY DRAG SLIGHTLY THE MORE FLUID HELPS THEM TO DISSIPATE THE HEAT FROM THE FRICTION. THE LARGER THE VOLUME THE LESS PRESSURE IS NEEDED TO OPERATE THE CALIPERS. USUALLY AROUND 2 PSI OR SO.
THE REAR WHEEL CYLIDERS MOVE FARTHER AND REQUIRE MORE PRESSURE TO KEEP THEM FORCED AGAIST THE DRUM. 10 PSI IS THE NORM. THAT IS WHY THE LARGER LINE IS RUN TO THE REAR, IT CAN HANDLE THE PRESSURE AND FLUID NEEDED TO ACCOMPLISH THIS.
PUSHING THE PEDAL, THE REAR RESERVIOR REACTS FIRST THEN THE FRONT.
USUALLY THE DRUMS ARE THE REAR RES. BECAUSE IN LIGHTER BRAKING BY LIGHTLY APPLYING THEM, LESS CHANCE OF LOCKUP. THE HARDER YOU PUSH, THE MASTERCYLINDER APPLIES MORE TO THE FRONT TO AVOID LOCKUP IN THE REAR, BECAUSE THE WEIGHT TRANSFER TO THE FRONT THE DISCS HAVE A BETTER CHANCE OF NOT LOCKING UP UNDER MORE PRESSURE, AND THEY STOP BETTER. ALL THIS IS ACCOMPLISHED BY THE CORRECT BOOSTER/MASTER COMBO, VACCUUM TO THE BOOSTER AND A PROPERLY FUNCIONING PROPORTIONING VALVE.

SORRY ABOUT WRITING THIS NOVEL, BUT SHORT AND SWEET WOULD LEAVE TOO MANY QUESTIONS I FEAR.

HOPE THIS HELPS,

BRANT
 
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