Hello,
I've purchase an 06 Envoy XL Denali 5.3L from scrapyard that seemed to be in good mechanical condition.
Based on the tires and the spare it came with, I suspect that the car's been sitting since 2011 (tires are 2010 and spare is 2006).
After fabricating a key, it started right up (yay... not) everything seems to be running except for the brakes. The hydraulics of the brakes, to be specific.
In the beginning there was on oil going to the front calipers and the rears were always engaged. After examination turns out the oil goes into the ABS, but doesn't come out to the fronts. Purchased one from scrapyard and tried to install it myself, but this POS didn't want to cooperate. Got 2 brake lines cross threaded and started leaking.
I then purchased another ABS module and let a garage deal with it. It got installed with no leaks to be seen. There was good pressure at the front and back. However, when testing it turns out that the master cylinder can't hold the pressure.
If you press the pedal 3~5 times and hold, the car won't move when put in drive. But if you release and press and hold 1 time after that, the brakes won't hold.
On top of that, in the very beginning the brake booster wouldn't budge (seems like a repair was already attempted before ditching the car in scrapyard, it was installed upside down and repair markes on the housing were visible). So I took it to a guy who fixes boosters and he told me the piston wasn't installed correctly and that it was binding/locked in place. After he fixed it I installed it on the car and a vacuum leak sound appeared and it would go away when I press the brake. I ignored it because at least I could now test the brakes.
After getting the ABS replaced and having pressure in front and back, the garage owner told me to get the booster fixed before continuing so I took it back to the same person and he told me that some part was broken inside and he replaced it. Now there is a vacuum leak sound as soon as I press the brakes.
After figuring out that the master cylinder needs replacement, I'd decided to buy a booster/master combo coming from the same vehicle (preferably). It took me like 7 hours to find them (the 5.3L Envoy is extremely rare here in Qatar).
In the end, I took the booster/master from the same car that I took the first ABS from. This car supposedly stopped 2 months ago due to a transmission problem and the garage bought it from the customer and the took the engine for another car.
After having them installed, the frond driver's caliper bleed screw was removed and a hex screw was shoved in place to stop the oil from coming out. It was like that when I purchased the car and the garage kept holding it off and delaying it. After we got almost everything replaced I bought another front driver's caliper from scrapyard due to the screw that was shoved and mainly because one of the pistons was chipped. We thought this is the last piece of the puzzle and that everything would work beautifully now... Yeah, right..
So after installing the booster/master and replacing the front driver's caliper, the garage attempted a (supposedly final) brake bleed. There was good pressure at the front, but not so much at the back. However, the car is able to stop using the front brakes.
The garage owner told me to take the car for a spin around the garage and use the brakes a lot. He said this is supposed to get the pedal firmer (trapped air moves to different location) and he'll bleed it again.
Needless to say, the pedal didn't get any better, but at least the front brakes are working now. He then decided to try the old master cylinder again since that one was providing good pressure to both front and back. After getting it installed the bleeding attempt failed. Now there's no pressure at all neither the front nor the rear. Then he installed the new one again and same thing, no pressure at the front (which previously had good pressure) and no pressure at the rear.
He was very stubborn when I talk to him about my findings on the Internet to the point that he told me to either go his way (with his 20 years of experience) or go with the Internet. This talk was in the first couple of days when I put the car in his garage, so I told him to do whatever he wants but I need it fixed.
After all this, he gave up confused and I told him there must be air trapped in the ABS (he kept blaming the booster and master cylinder).
Having spent so much money on this car, my father decided that we should take it to the stealership, and we did. I have agreed with them to bleed the system and go from there. The next day they infirmed me that I need to purchase a new master cylinder, Brake Booster, ABS valve modulator & E.B.C.M. I believe they didn't do the bleed that we agreed on and they just put this list (I had previously told the stealership what was done before bringing the car). Going back and forth they told me that the E.B.C.M wasn't responding to the bleeding command (which I still feel that he didn't do, he doesn't want to give me details), and I told him I have 2 in the car and he kept repeating you can't buy from scrapyard it has to be new and ordered based on the VIN number etc etc...
They didn't have the E.B.C.M in stock so he gave me the part number and told me to order online or bring it from the surrounding countries. I checked the ones that I had from scrap yard and they were the same part number and now he got a little convinced to try them.
He's requesting about $350 to program 1 of them to the car and do the manual and scanner bleeding, with no guarantee that this would work and we'd have to pay the same amount to try the other one if this one doesn't work. After further discussion, he offered to try both for $430.
If we don't proceed with the stealership we'll have to pay $150 for inspection fees.
What do you guys suggest?
I've purchase an 06 Envoy XL Denali 5.3L from scrapyard that seemed to be in good mechanical condition.
Based on the tires and the spare it came with, I suspect that the car's been sitting since 2011 (tires are 2010 and spare is 2006).
After fabricating a key, it started right up (yay... not) everything seems to be running except for the brakes. The hydraulics of the brakes, to be specific.
In the beginning there was on oil going to the front calipers and the rears were always engaged. After examination turns out the oil goes into the ABS, but doesn't come out to the fronts. Purchased one from scrapyard and tried to install it myself, but this POS didn't want to cooperate. Got 2 brake lines cross threaded and started leaking.
I then purchased another ABS module and let a garage deal with it. It got installed with no leaks to be seen. There was good pressure at the front and back. However, when testing it turns out that the master cylinder can't hold the pressure.
If you press the pedal 3~5 times and hold, the car won't move when put in drive. But if you release and press and hold 1 time after that, the brakes won't hold.
On top of that, in the very beginning the brake booster wouldn't budge (seems like a repair was already attempted before ditching the car in scrapyard, it was installed upside down and repair markes on the housing were visible). So I took it to a guy who fixes boosters and he told me the piston wasn't installed correctly and that it was binding/locked in place. After he fixed it I installed it on the car and a vacuum leak sound appeared and it would go away when I press the brake. I ignored it because at least I could now test the brakes.
After getting the ABS replaced and having pressure in front and back, the garage owner told me to get the booster fixed before continuing so I took it back to the same person and he told me that some part was broken inside and he replaced it. Now there is a vacuum leak sound as soon as I press the brakes.
After figuring out that the master cylinder needs replacement, I'd decided to buy a booster/master combo coming from the same vehicle (preferably). It took me like 7 hours to find them (the 5.3L Envoy is extremely rare here in Qatar).
In the end, I took the booster/master from the same car that I took the first ABS from. This car supposedly stopped 2 months ago due to a transmission problem and the garage bought it from the customer and the took the engine for another car.
After having them installed, the frond driver's caliper bleed screw was removed and a hex screw was shoved in place to stop the oil from coming out. It was like that when I purchased the car and the garage kept holding it off and delaying it. After we got almost everything replaced I bought another front driver's caliper from scrapyard due to the screw that was shoved and mainly because one of the pistons was chipped. We thought this is the last piece of the puzzle and that everything would work beautifully now... Yeah, right..
So after installing the booster/master and replacing the front driver's caliper, the garage attempted a (supposedly final) brake bleed. There was good pressure at the front, but not so much at the back. However, the car is able to stop using the front brakes.
The garage owner told me to take the car for a spin around the garage and use the brakes a lot. He said this is supposed to get the pedal firmer (trapped air moves to different location) and he'll bleed it again.
Needless to say, the pedal didn't get any better, but at least the front brakes are working now. He then decided to try the old master cylinder again since that one was providing good pressure to both front and back. After getting it installed the bleeding attempt failed. Now there's no pressure at all neither the front nor the rear. Then he installed the new one again and same thing, no pressure at the front (which previously had good pressure) and no pressure at the rear.
He was very stubborn when I talk to him about my findings on the Internet to the point that he told me to either go his way (with his 20 years of experience) or go with the Internet. This talk was in the first couple of days when I put the car in his garage, so I told him to do whatever he wants but I need it fixed.
After all this, he gave up confused and I told him there must be air trapped in the ABS (he kept blaming the booster and master cylinder).
Having spent so much money on this car, my father decided that we should take it to the stealership, and we did. I have agreed with them to bleed the system and go from there. The next day they infirmed me that I need to purchase a new master cylinder, Brake Booster, ABS valve modulator & E.B.C.M. I believe they didn't do the bleed that we agreed on and they just put this list (I had previously told the stealership what was done before bringing the car). Going back and forth they told me that the E.B.C.M wasn't responding to the bleeding command (which I still feel that he didn't do, he doesn't want to give me details), and I told him I have 2 in the car and he kept repeating you can't buy from scrapyard it has to be new and ordered based on the VIN number etc etc...
They didn't have the E.B.C.M in stock so he gave me the part number and told me to order online or bring it from the surrounding countries. I checked the ones that I had from scrap yard and they were the same part number and now he got a little convinced to try them.
He's requesting about $350 to program 1 of them to the car and do the manual and scanner bleeding, with no guarantee that this would work and we'd have to pay the same amount to try the other one if this one doesn't work. After further discussion, he offered to try both for $430.
If we don't proceed with the stealership we'll have to pay $150 for inspection fees.
What do you guys suggest?