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Silverado brakes locking up.

Capt. Delta
08-02-2006, 09:10 PM
OK I'm at the end of my rope. Don't know much about "forums" but hope somebody out there can give me some feedback.

Own a 99 Chevy Silverado Z71. In Oct. 05 brakes began locking up for no reason. Took to the dealer who said system was contaminated by power steering fluid or something similiar. Charged me $3000 to replace the entire brake system not including pads and rotors. (Wanted another $1400 to replace those.) Day after they replaced system I put new pads/rotors on. Worked fine but I noticed a lot of brake dust on my wheels. Also rotors turned blue within a month. Dealer said could do nothing about blue rotors since they didn't put them on.

Last week my "chirpers" went off. Brakes down to nothing after only 12,000 miles. Put new high performance drilled/slotted rotors and new pads on. Within a day the brakes were locking up again. Not even when I was braking. Just driving down the freeway and all of a sudden the front end starts shuddering. Pull over and smoke is coming off the front brakes.

Took it back to the dealer under the repair warrranty. They gave me the old "could not duplicate" runaround. Even though they admit my new rotors should not be blue in a week. Anyone out there who has had similiar problem. I'm thinking stuck caliper or ABS malfunction but dealer sez they are working fine.

Blue Bowtie
08-02-2006, 09:53 PM
Does the truck have hydraulically assisted power brakes? Ask the dealer about the TSB for a brake booster problem.

Capt. Delta
08-03-2006, 02:29 AM
No hydraulic assist. It's a 1500 4 wheel drive. I'm beginning to think it has to be something to do with the ABS. It will lock up when I'm just driving on the freeway. Not even touching the brakes and suddenly front end will start shaking. By the time I pull over there is peddle fade from the heat and the front brakes are smoking. I've never seen anything like it. Dealer keeps saying bring it too them the next time it does that. Hell unless I'm right next door the whole thing will have burned up by the time I get there. Thought maybe it might be the proportioning valve but dealer sez the truck doesn't have one. It's all part of the ABS module.

I used to love Chevy's but I'm beginning to get real sour

08-03-2006, 03:16 AM
Try pulling the ABS fuse and see if it repeats. It's going to throw a trouble code when you do, BTW.

Capt. Delta
08-03-2006, 09:57 AM
Great minds think alike. I was laying in bed thinking about the problem and thought of the same thing. Then saw your post this morning. Will try it and let you know.

08-03-2006, 08:49 PM
I have 99 sierra 1500, with the 4 wheel disc brakes, and mine was doing it once in a blue moon, during city driving. DID you get the RECALL about the abs sensor for all 99 to 2001 trucks? If not i would look into that, thats what was wrong with mine i can get you the recall code if you would like also.

Capt. Delta
08-04-2006, 12:17 AM
Thanks "Trucks" Yes could you get me that recall code. I'd love to wave it in the dealers face. They said they checked and there was no recall on any Silverado brake parts. I assume a Sierra and a Silverado would have the same brakes.

Here's the latest on the brakes. After the dealer telling me there was "nothing wrong" I got up this morning and drove around the dealership til they locked up. Then drove up to the service door with the brakes smoking and dared em to tell me nothings wrong. They took it in and now tell me the calipers are sticking. DUH!!! This after telling me yesterday everything was fine. The kicker is they say since its 13,000 miles since they did the brake work the warranty doesn't apply. (Their warranty is 12 mo 12,000 miles) This even though my wheels have been covered with brake dust since the day I paid them $3000 to make my brakes right. But as a "favor" they said they went to bat for me with GM and are willing to put new calipers on at no parts charge if I pay the $210 labor. What a crock. I'm in law enforcement and in my line of work they call that "an admission of guilt." Of course they won't do anything about the expensive drilled/slotted rotors and pads I put on a week ago and are now ruined. But I'm over a barrel and will pay the labor.

Thanks to everyone for their input on this.

Capt. Delta
08-04-2006, 12:38 AM
Hey "Trucks" Unfortunately i don't think your recall code will not apply to me. I looked on the net and only found an ABS recall for the "salt belt" states. Guess us Ca. people who live near a salt filled ocean don't count. But send me the recall code anyway. Thanks for the help.

08-04-2006, 12:40 AM
You mean for $3000 and they didn't touch the calipers? dumbasses.. I assumed with that much money spent, they would at least inspect them for binding....Hell, 3 grand would buy me a complete system.

Capt. Delta
08-04-2006, 04:32 AM
Thats my point Corning. They DID replace the entire system in Oct 05. Master cylinder, lines, ABS etc. THEY decided to rebuild the calipers to "save me money" Only thing they didn't do was the rotors and pads. Wanted an additional $1400 for that. I'd had enough. Whats it take 5 minutes to remove the caliper bracket put on the rotor once you already have the car apart. (By the way lest you think I'm just dripping with money most of this was paid for by my insurance company but thats another story.) I put on Raybestos rotors and Duralast Gold pads the day after I got it back from the dealer. When I took it back to them 2 months later cause the rotors were blue their excuse was it must be the rotors and pads I used. Now even though they're admitting the calipers are sticking they refuse to admit its what caused my pads to wear out in 13,000 miles or the problem began while it was under warranty. By the way I don't tow anything, I don't live in the mountains, and I don't have a heavy brake foot.

08-04-2006, 11:02 PM
That's the reason I enrolled myself in an auto service class at my local tech college. Now, the parts are the same price, but the labor is free!! I don't think all dealers are rip-offs, but over 80% I've been to are..

Capt. Delta
08-06-2006, 09:06 AM
Well here's the latest in the smoking brakes saga. Left it with the dealer to put on new calipers. (That was after I drove in with smoking brakes and they finally admitted something was wrong) Reiterated to them I thought it was the ABS. They later told me the on board computer gave no indication the ABS had activated. Wife picked it up cause I was at work. Paid the $210 that should have been covered under warranty. Got up the next morning to drive to work. Brakes locked up within 5 miles. At that point it wasn't just the brakes that were smoking. I should have taken your advice Corning, instead of believing a thing the dealer said. Pulled the ABS fuse and the brakes unlocked. Been driving it all weekend with no problems other than the ABS/brake lights being on. Will be at the dealers door first thing Monday morning to get my pound of flesh. I'm sure they will say "you were a thousand miles out of warranty so we're doing nothing. Even though they put in a new ABS when they replaced the original brake system. I'm thinking now they misdiagnosed the whole problem back in Oct 05.

Nobody likes to pay the exorbitant dealer costs but when you do go to them you expect you're getting experts to work on it instead of a bunch of buffoons.

I'm sure I'll be replacing the ABS on my own. I have a friend who owns an auto parts distributership. He'll get it for me at cost. Anyone replaced one that can tell me how hard it is to do.

08-06-2006, 11:18 AM
This is the place to go for all ABS problems
He saved me about $1500. The ABS system is in three parts...the sensors, EBCM computer and ABS pump. The sensors or on the two front wheel hubs and one in the back. The EBCM is on top of the ABS pump on the frame rail about where the drivers door is located. Throw a blanket down or use a creeper and you can look up and see where about seven brake lines go into a metal box...that's the pump. The good news is if you need the EBCM worked on you can still drive the just have to wrap plastic over the pump housing after you remove the ECBM. The ABS light will stay on and you won't have ABS protection. The torx bolts that hold the ECBM on are steel and probably rusted so you have to cut them off. Modulemaster sells stainless steel bolt replacements. What I did was have Gavin at ModuleMaster rebuild my ECBM while I drove the truck...he sold me a refurbished ABS pump and when I got the two units I swapped out the old ABS pump and reinstalled everything and it worked great...for awhile. I kept having the ABS pump come on at low speed and I almost ran into several cars. It was a bad sensor which I replaced the entire hub and now everything is fine. GM had an ABS recall about the sensors and they paid me back for the hub ($150) and replaced the other sensor.

08-06-2006, 12:36 PM
At least you found the problem, but if your luck with dealers is as "good" as mine.....Reminds me of having to fight with my ins. company for shoddy paint work..I've been going around for a month now.

Capt. Delta
08-07-2006, 12:38 AM
Thanks for the input "Sonny. I'm going back to the dealer tomorrow to do battle. I'm sure they will tell me to pound sand. The recall only applies to "salt belt" states or at least from what I've read. I'm thinking it is the speed sensors. This is based on the fact the ABS light never came on. I've also never heard the ABS motor continue to run after I turn off the vehicle as many have described in thier complaints. Somewhere in all the Internet research I've done I read that when the sensors go bad it will not show up on the vehicle computer. The dealer said there was no record of ABS malfunction or trouble codes. The dealer also said they replaced the ABS motor/module when they did the work in Oct 05. In the recall bulletin for the speed sensor it lists the things the dealer is supposed to do. Remove sensor, clean all rust off, apply rust inhibitor/grease etc. Since you've done one is there much too it? I've looked at its location in the shop manual but thats as far as I've gotten

08-07-2006, 12:25 PM
You can get to the sensor by removing a front tire. It's attached to the wheel hub and easy to get to. After you get it all cleaned up and reinstalled find where it plugs into and disconnect it (normally up in the engine compartment). Plug an AC volt meter into the sensor line...reinstall the tire and give it a spin while watching the meter. Anything under 350 is bad and you either need a new sensor or the rust has moved the sensor so far away from the ring inside the hub it can't get a good hit as it moves past it. Do the other side...if you get a good reading put that sensor on the bad side and spin it again. If the voltage is up then the original sensor is bad. If the good sensor is now bad you need a new hub or more rust removal...get a new hub. But first I'd contact Chevy and argue with them about your truck being a possible lawsuit down the road. Try the dealer first then Corporate GM.

Capt. Delta
08-07-2006, 01:37 PM
You've been a big help Sonny. I took it to the dealer this morning. I handed them their own TSB and recall bulletins that I had downloaded from the net. They couldn't even find them on their own computer. Have you seen the commercial where the guy is working with a bunch of monkeys. I always wondered where that company was located. Now I know. They're looking at the truck as we speak.

We did have a serious "chat" about customer service and competent mechanics.

I assume when you said 350 that would be in milliamps or millivolts. Are there two wires on the electrical connector? One for each probe on the tester or just one wire (+) and the other to the body (-) If two, does it matter which one goes into which and this has to be an AC tester not a DC tester, right?

Hopefully I won't have to deal with it and they will make it right. Maybe I should bring them a shop towel to wipe the egg off their face.

08-07-2006, 02:59 PM
Capt. Delta...are you a pilot?
Here it is...I just found it...02-05-25-006A ABS Activation at Low Speeds (11/26/02).
350 AC Millivolts. HeHe I forgot to make it .350...I knew what I meant...I just didn't pass it along.
If you get the wires backward it will still works just fine...what won't work is to ground the - voltmeter lead and then try for a reading on the - wire from the sensor.

Capt. Delta
08-07-2006, 09:28 PM
Sorry not a pilot. I'll send you a seperate E-mail message to explain Capt. Delta so as not to clutter the forum up.

Dealer called this evening and said the sensors are not bad. They're going to check a few more things in the morning and take it for a test drive. (DUH!!)

They asked if the problem started when I put the new slotted/drilled rotors on 2 weeks ago which it didn't. Just got more exagerrated. I can see where they are going to try and go with this. Lets see...ABS fuse in brakes lock up, ABS fuse out breaks work fine. I think even a chimp can figure that one out. But in fairness I guess they are exploring all possibilities. I've spent so much time at the dealer I'm going to have to add them to my Xmas list or some other more appropriate list.

08-07-2006, 10:10 PM
I have a complete set of Brembo slotted rotors and NAPA pads on my truck and with the exception of the front rotors needing to be turned...which you can't do...they are just fine and the system works the way Chevy intended it to, after everything has been upgraded or replaced of course. I bought a set of the cross drilled Brembo's to put on the front, which is what the factory (Brembo) says I should have bought in the first place. The entire brake system is weak if you ask me but once you buy the truck you have to make things work. I drove a friends Ford and about put everybody thru the windshield the first time I used the they were nice. I'm still not going to buy one though.

Capt. Delta
08-09-2006, 09:42 AM
VINDICATION!!!!!! Got a call from the dealer yesterday afternoon tellin me they had driven the truck 7 miles and no brake problems. ARRRRGH!!! I figure at that point they think I'm some crazy mutant. I told the service manager to take the car home with him that night and if no problems I'd pick it up this morning. Got a call at 7 AM. Said he drove it home with no problems. He lives "uphill" from the dealership. Going "downhill this morning the brakes started shaking violently. At least now they know I'm not a nut case. I also noticed the brakes would usually malfunction when I was going downhill and not applying the brakes. (Long slow freeway downgrades.) They also asked how long the truck has had a trailer brake controller. (Were on there when I got the truck 3 years/70,000 miles ago.)

They'll be calling the GM tech's today.

My question is: Has anybody ever had problems with a trailer brake controller activating the ABS?

08-09-2006, 10:41 AM
You don't by chance have a Prodigy brake controller do you? They have an internal device for controlling the brakes when you go up or down a grade so you don't have to futz with the controller setting. Going down it would activate the trailer brakes harder. I can't see how it could interfere with the truck brakes though.

Capt. Delta
08-10-2006, 07:44 PM
Well here's the final from the dealer. They've had my truck for 3 days. Been in contact with the GM techs and they're all stumped. They disconnected the trailer brake controller and didn't cure the problem. Cleaned the speed sensors and no dice. Now they say it must be in the EBCM module and want $1200 to replace it. However they won't guarentee it will fix the problem. Hell if I'm going to spend $1200 on the "by guess and by golly" method. Only thing I can think of is to get one from a wrecking yard and put it on to see if it fixes the problem. I've also heard of places that will rebuild the unit. Anyone have experience with taking one off?

08-10-2006, 08:18 PM
Don't buy one from a wreaked might not work with your truck. Look back in this thread to 08-06-06 and I think I answered your question about taking the ECBM off. Before you Gavin at ModuleMaster listed in my post...he'll get you fixed up.

08-10-2006, 09:30 PM
it took me kidnaping the service manager to get them to drive my truck till the problem started. my abs will start kicking in when the truck gets all nice and warmed up. normly around 40+ miles. thay would only diver the truck 1 mile 2 at the most.

drove to the next town and back then the abs started kicking in the manager told me i was not pushing on the brake enuff to fake it. till i stoped and told him well drive it. the first stop sign we came to the abs kicked in and we went right thru it. when we got back to the shop thay put the computer on it and said well there are no codes but we do have a problem some ware. come back when the abs light stays on.

Capt. Delta
08-11-2006, 08:55 AM
Thanks Sonny. I guess I better start opening my AARP mail cause I'm gettin senile. Should have looked back through the threads. I'll be sending it off to ModuleMaster next week when I get time to take it off. I've seen other companies that will do it cheaper but it sounds like you've had good luck with them. Their web site certainly does a good job of selling their superior product. I'll let you know if it works but it will be a week or two.

Capt. Delta
08-15-2006, 11:25 AM
"Sonny" Talked to Gavin at Modulemaster yesterday. Told him about the problem. He doesn't think its in the EBCM. Said he has heard of this on rare occassions where there is an intermittant break in the wiring. Usually in the harness where it goes between the frame and the body. Very helpful gentleman to talk to. Said it is probably the yellow/black wire that comes off the module. Went ahead and sent him the module to have it tested first. Last thing I want to do is start breaking into the spaghetti of wires looking for a break. Said there's no charge for testing the unit. Sent him a check anyway. Think I'll go ahead and upgrade it as long as he's got it even if sez working fine.

08-15-2006, 03:57 PM
It's a good idea to upgrade the you can drive and if the brakes act up again then it's not the ECBM or the ABS system. I'm glad you're making progress. I hope Gavin fixes the problem for you.

Capt. Delta
08-27-2006, 10:51 AM
Arrrgh!!! Got the EBCM back from ModuleMaster. Put it in and the same problem. I did call but was not able to talk to Gavin. Their file did show a DTC of E265 (Open relay circuit) when it was brought in. I have to talk to Gavin and find out if that error code would have been caused by removing the fuse. If not I'll be tracing every damn wire from the EBCM. That will be a nightmare.

08-27-2006, 10:57 AM
Man...that's a tough one...I'm going to read thru all of your posts and see if I'm missing something.

08-27-2006, 11:24 AM
What a horror story.

Its seems somebody has to get killed to get satisfaction.

If you drove the truck thru their showroom window.....

Maybe if you could dig up a little dirt on the dealership, since your in the business. Make them sweat a little.

Capt. Delta
10-21-2006, 03:57 AM
Haven't given an update on the brakes in a long time cause was still trying to figure out what the hell was wrong. First off you were right Sonny. Gavin at Modulemaster was awesome. Must have talked to him 8 or 9 times and he always went step by step through the troubleshooting. At one point he even shipped me his back-up ABS scan tool to do some tests at no charge.

Now for the solution. Got the rebuilt ABS back and still had the problem with brake lock-up. Gaven said it had one bad solenoid but should not have caused lock-up. I ran it for awhile with the fuse out cause I was just getting too frustrated to work on it anymore. I did notice even with the fuse out there was a little shudder at high speeds but not near as severe as when the fuse was in.

One morning I raised the front tires while truck was cold. Wheels turned freely. Started the engine and pumped the brakes a few times. Now the wheel would turn but took both hands just to turn it. I then loosened the two nuts that hold the master cylinder to the power booster. Sure as hell the brakes released. Only had to back them off about a 1/16th of an inch. Noticed there was no gasket between the m/cylinder and power booster. Checked the Chilton manual which said there should be one. Went back to the dealer to "discuss" why their mechanics forgot to put in the gasket. According to their shop manuals there is no gasket used. They called Detroit who said there was one known instance of a booster piston being machined too long but since I had replaced the booster from a parts house when all my problems started there was nothing they could do.

So I wound up making a new gasket out of 1/16" material and sure as hell my brakes are working perfectly.

A years worth of frustration all because of a damn gasket.

10-21-2006, 08:20 AM
What a bunch of crap. The dealer owes you service to correct the problem completely.

If you end up doing the job yourself, try this guy. I've gotten great products from them. Good prices too. Search ebay for silverado hub. he has other zero mile parts as well. QQitemZ230040004429QQrdZ1QQsspagenameZWDVW

Or this guy has an exact application: emZ270039182125QQrdZ1QQsspagenameZWDVW

Blue Bowtie
10-21-2006, 10:16 AM

Good to see that you've resolved the problem. If you want to pursue it further, visit a different dedalership parts counter, and ask to look at the parts breakdown for the power booster and master cylinder on your truck. The diagram should show whether a gasket is installed there or not.

11-21-2014, 01:25 PM
Am having the same problem. I have replaced the power booster (2 times) master cylinder all the brakes pads. When it locks up all the wheels stop. It slides the tires. I get out and release the pressure at the master cylinder and am good to go for a day or so. I put a gasket between the power booster and master cylinder and it does the same is a 99 chevy 2500 pickup. Is there a posability that the power stearin
g pump or hoses to the hoses to the power booster (hydrochloride booster ) might be bad.

j cAT
11-21-2014, 02:22 PM
Am having the same problem. I have replaced the power booster (2 times) master cylinder all the brakes pads. When it locks up all the wheels stop. It slides the tires. I get out and release the pressure at the master cylinder and am good to go for a day or so. I put a gasket between the power booster and master cylinder and it does the same is a 99 chevy 2500 pickup. Is there a posability that the power stearin
g pump or hoses to the hoses to the power booster (hydrochloride booster ) might be bad.

how long you owned this ?

what can happen is if the fluid is contaminated then the master will swell up and stick in the apply position. remove master and check that this is not occuring. only use new brake fluid. any mineral oil in the brake fluid will do this even just a drop...

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