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Power Brake Booster? 2000 CHEV K3500 6.5L Diesel

OBE

OBE

Member
Messages
129
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25
Location
Blackwood, NJ
Latest development: I put some freon in it and the darn thing started making cold air! lol In all the time I had it I never even thought to charge the A/C. BUT, I took it for another test drive, and while sitting at a red light, the brake pedal is fading away under my foot. What now?
 
Check for leaks, brake lines, wheel cylinders, master cylinder, rubber flex lines, etc.

If it ain't one thing it's four, right?
 
In other words, there are some leak in the brake system.

I would not drive the truck in that condition.

If you want to fix it fast, bring it to a mechanic or brake shop.
 
3500GMC said:
Check for leaks, brake lines, wheel cylinders, master cylinder, rubber flex lines, etc.

If it ain't one thing it's four, right?
Click to expand...
My reg driver is the '97 Sierra and it had that problem (blown-out brake line) but I don't drive this one. Only to run it down the road a little.
 
Look for leaks. It's either leaking fluid externally in which case you should be able to find fluid somewhere from a brake line, caliper, or wheel cylinder. Or it's leaking internally in the master and the fluid is going back to the reservoir. It's not rocket science, just gotta find where the fluid is going.
 
Thanx Fermanator: One curiosity: I took it into my oil change shop because I was driving-by and noticed they weren't busy. Rather than deal with the mess, I let them do it. Now, they give it a going-over to see if anything's amiss and noted that the brake fluid was low (but they didn't add any!) Right after the oil change is when I noticed the fading pedal. I took the cover off the MC but I didn't notice that it was replaced incorrectly; only that it was about half-full so I topped-it-off.

I did a fast check of the tires for wetness and the frame rails but saw nothing.
 
I never add brake fluid. why? When the pads/ shoes wear out, the fluid will be low. When the fluid is low, replace the pads/ shoes and the fluid will be perfectly full again. As it is a sealed system, you should never have to add a drop.

Just make a note at regular intervals to flush the old fluid with new- I do 100,000 miles.
 
I replace my brake fluid every 3 years. I have noticed since I switched to dot 4, it stays ALOT cleaner. After 3 years dot 3 would be showing definite signs of moisture intrusion(it's unavoidable as regular dot 3 is a very aqueous solution, and pulls moisture from anywhere it can), but the dot 4 still looks almost as good as fresh out of the bottle. And since brake fluid is an aqueous solution, once it's opened, you need to use it. You don't want to use a bottle that's been opened and left on the shelf for more than a year IMHO.
 
2 key things to note- Ferm lives in a very humid area. I am in about the driest place in the country, and use dot5.

With no humidity here, dot3/4 will survive much longer. There are simple test strips you can use to test for moisture if you are not sure, but a simple flush takes only a couple hours. 3 years sounds reasonable and safe to me in a humid area.

dot 5 is silicone based and does not absorb moisture. Many people switch their system to dot5 because of this and it's higher boiling point. I do not recommend this, because anytime you switch from one fluid base to another leaks can begin. For those that will switch from, understand you need to disassemble master cylinder, calipers, proportioning valve and replace O-rings, possibly flexible lines replaced also.
 
Anytime we go anywhere 250 miles away, I have to hear my wife: "Oh I love how my skin and hair feels!"

Breathe air. Drink water. Don't mix the two, that's my theory.
 
Will L. said:
2 key things to note- Ferm lives in a very humid area. I am in about the driest place in the country, and use dot5.

With no humidity here, dot3/4 will survive much longer. There are simple test strips you can use to test for moisture if you are not sure, but a simple flush takes only a couple hours. 3 years sounds reasonable and safe to me in a humid area.

dot 5 is silicone based and does not absorb moisture. Many people switch their system to dot5 because of this and it's higher boiling point. I do not recommend this, because anytime you switch from one fluid base to another leaks can begin. For those that will switch from, understand you need to disassemble master cylinder, calipers, proportioning valve and replace O-rings, possibly flexible lines replaced also.
Click to expand...

Do not mix DOT 5 with anything else as the combo will screw things up. You can watch it "clump" and not mix well going in. It's not like 50 weight engine oil, just another grade of better fluid, as the numbers would have you assume. Replaced an entire brake system after this foul up. MC failed and everything rubber leaked.
 
HOLY COW! I just finished it. It took me a damn week! It was a leaky wheel cylinder on the right rear. Every thing I put a wrench on BROKE! I replaced brake line, wheel cylinder, and shoes. Sounds easy when you say it fast. Pulling apart full-floating dual-wheel rear without a lift...not something you want to do. The springs are behind the wheel cylinder so you can't hardly get your hands in there to turn a bolt. All of the bleeders (on the other three wheels) were frozen! I had to bleed using only the rt rear new bleeder...NIGHTMARE! I couldn't get at the bleeder to put a hose on it so I had to bleed it over and over again the old fashioned way. I finally got it.
 
This is where it is frustrating working in a maintenance shop. The owners say "WHY! did it take five hours to change out the thingamajig?.....There is only five bolts, I probably could have done it in five minutes."

And you think..............."yea but it took me four hours and fifty six minutes to get ONE of those bolts out!"
 
When they changed the motor they hooked everything up but they didn't get the AC working. I never bothered with it all the time I had it because I don't really care about AC. But one guy asked me (I decided to sell it since I don't use it anymore to tow) if the AC worked and I thought I ought to see if I could charge it.

I put 2 lbs of 134A in and the compressor kicked-on and the darn thing started blowing cold air into the cabin. I was shocked. The blower would run only on HIGH, though, and it would run you out of the truck! I replaced the resistor and got the blower working on all speeds and thought I was home free. A couple days later, though, the 134A had leaked out.

I bought some Red Angel sealer ($35 for a little bottle) and put it in but it still leaked out again. Today, I put some dye in it and refilled it with 134A. It leaked out again but I don't see any red dye marks! I bought a set of gauges at Harbor Freight but I don't really have any experience with AC. I'm following the directions (as I am with all these repairs I've been doing)

I bought a vacuum pump and sucked everything out of the system. I put a vacuum on it and made a note of the time and the loss of vacuum. It was just under the minimum recommended by Red Angel. The instructions say if it won't hold 25 for 5 minutes OR 5 for 25 minutes it's leaking too bad. It was just about at those numbers. It leaked out in about a half-hour.
 
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