CUCV brakes dragging....

[Sarge]

So..... The title pretty much says it....
My M1009 front brakes are dragging. After 10 miles they are warm, after 25 miles they are way too hot to touch. And smelly!
First I replaced the pads, no improvement.
I did not replace the rotors, they look almost new.
Then I replaced both front calipers and hoses, no improvement.
I have tried throwing money at this problem, no good so far.
I have tried searching Steel Soldiers, no good so far.
So what is the magic fix?
What is wrong with my CUCV?
When will I win the lottery?
If I change the master cylinder, will it fix my problem?
Or is it something else?
Am I too ugly to own a CUCV?
Help me Obi-Wan, you're my only hope!
-Sarge

 

[TyJustice]

I have the same problem with my CUCV!! Just had new brakes and bearings installed. Having the same heat issue as the OP, is this normal or do I need to be concerned?

 

[doghead]

Maybe a sticking proportioning valve? It's on the frame crosmember, under the engine.

 

[reloader64]

Sarge, master cylinders rarely stick, but I suppose it's possible. If it was sticking, I would think the pedal would have a lot of play, and then hit solidly. It may be that you are too ugly to own a CUCV, but I doubt it, being the handsome devil that you are. Doghead may be on to something. Of course, at this point, there is little left to replace besides the proportioning valve and the master cylinder.

Scott

 

[GreenBull]

The following advice is valid for a vehicle with clean uncontaminated brake fluid and properly assembled brakes.

First check is to pull up on the brake pedal. If it clicks then the brake lamp switch was missadjusted and you have solved the problem.

Lift one of the problem wheels from the ground and check the drag on the wheel rotation both cold and when the problem is duplicated.

Next crack a bleeder while the problem is present. You will get a squirt of fluid from the bleeder if its a residual pressure problem.

If it is, duplicate the problem again. Without disconnecting anything else loosen the master cylinder from the booster.

If the drag is gone its pushrod/booster/pedal related.

If the drag is still present its hydraulic and likely master cylinder related.

I'm betting on the missadjusted stop lamp switch.

I hope this helps.

 

[army98]

My 1031 brakes (front) drag some and the only thing that helps is I grease the rails (mounting ) for the calipers seems to stop it every time.

 

[Recovry4x4]

Greenbull has explained it nicely and even covered pushrod adjustment which can block the compensating port and cause the symptom. Good to have another brake minded person in the house.

 

[GreenBull]

Thanks Recovry4x4. I'll try to contribute.

Hey Sarge, what did you find?

Below is for army98. The specific recommendation for the Shell grease does not have to be followed as long as you use a high quality grease formulated for brake caliper slides.

#36-50-07: INFORMATION ON LUBRICATING CALIPER SLIDING SURFACES - (Nov 15, 1993)

SUBJECT:INFORMATION ON LUBRICATING CALIPER SLIDING SURFACES​

MODELS: 1991-94 CHEVROLET AND GMC C3500HD W/JF9 BRAKES 1973-94 G3 CHEVROLET AND GMC VANS W/JB8 1973-87 CHEVROLET AND GMC C/K 3500 W/JB8 1988-91 CHEVROLET AND GMC R/V 3500 W/JB8​

BRAKE WEAR IN THE ABOVE MODELS, MAY BE IMPACTED BY AN EARLY DEPLETION OF CALIPER RAIL SLIDE LUBRICANT. A LACK OF RAIL SLIDE LUBRICANT COULD RESULT IN PREMATURE BRAKE WEAR BY PREVENTING PROPER CALIPER ORIENTATION. VEHICLES OPERATING IN HIGH MOISTURE AND/OR DIRTY ENVIRONMENTS ARE MORE SUSCEPTIBLE TO AN EARLY DEPLETION OF LUBRICANT.
IT IS RECOMMENDED THAT AN AMPLE COATING OF AEROSHELL #5 GREASE BE APPLIED TO THE V-WAY SURFACES OF THE CALIPER HOUSING, THE ANCHOR PLATE RAIL SURFACES, AND THE CALIPER SUPPORT KEY, AFTER THOROUGHLY CLEANING THESE AREAS (SEE ILLUSTRATION). CARE SHOULD BE TAKEN IN KEEPING THE LUBRICANT AWAY FROM BRAKE PAD AND ROTOR SURFACES. THIS PROCEDURE SHOULD BE REPEATED AT THE TIME OF EACH BRAKE PAD CHANGE, OR WHENEVER THE CALIPER IS REMOVED FOR ANY REASON.
CURRENTLY THIS LUBRICANT CAN BE PROCURED FROM LOCAL SHELL DISTRIBUTORS OR THEIR RETAIL STORES IN VARIOUS SIZES INCLUDING 1 LB. CANS AND 14 OZ. CARTRIDGES, IN CASE LOTS.
WE BELIEVE THIS SOURCE AND THEIR EQUIPMENT TO BE RELIABLE. THERE MAY BE ADDITIONAL MANUFACTURERS OF SUCH EQUIPMENT. GENERAL MOTORS DOES NOT ENDORSE, INDICATE ANY PREFERENCE FOR OR ASSUME ANY RESPONSIBILITY FOR THE PRODUCTS OR EQUIPMENT FROM THESE FIRMS OR FOR ANY SUCH ITEMS WHICH MAY BE AVAILABLE FROM OTHER SOURCES.
FIGURES: 1​

GENERAL MOTORS BULLETINS ARE INTENDED FOR USE BY PROFESSIONAL TECHNICIANS, NOT A "DO-IT-YOURSELFER". THEY ARE WRITTEN TO INFORM THOSE TECHNICIANS OF CONDITIONS THAT MAY OCCUR ON SOME VEHICLES, OR TO PROVIDE INFORMATION THAT COULD ASSIST IN THE PROPER SERVICE OF A VEHICLE. PROPERLY TRAINED TECHNICIANS HAVE THE EQUIPMENT, TOOLS, SAFETY INSTRUCTIONS AND KNOW-HOW TO DO A JOB PROPERLY AND SAFELY. IF A CONDITION IS DESCRIBED, DO NOT ASSUME THAT THE BULLETIN APPLIES TO YOUR VEHICLE, OR THAT YOUR VEHICLE WILL HAVE THAT CONDITION. SEE A GENERAL MOTORS DEALER SERVICING YOUR BRAND OF GENERAL MOTORS VEHICLE FOR INFORMATION ON WHETHER YOUR VEHICLE MAY BENEFIT FROM THE INFORMATION.
COPYRIGHT 1993 GENERAL MOTORS CORPORATION. ALL RIGHTS RESERVED.​

 

[Sarge]

THANK YOU EVERYONE!!!
Tons of good advice in the above posts!
I never would have thought of the stoplight switch causing the problem, I checked it right away, mine was adjusted okay.
I am very familiar with the brake pad metal lips sticking on the calipers and not sliding freely, this happened on my civilian Jeep after a mere 250,000 miles. Ever since then I have greased my caliper sliding areas. I use anti-seize lubricant (the shiny stuff you use on nuts and bolts) because it is very high temp and does not melt off. I am not familiar with the Shell product. On my old Jeep, the calipers actually had grooves worn into them and replacing both calipers was the permanent fix. $30 for both, whoopy-tee doo.
Back to my M1009…..
After replacing both calipers and the hoses, no improvement in the dragging brakes.
Using the above advice, plus advice from Tracy, the best mechanic on the planet, this is what I did….
I jacked up the front and the wheels were still dragging.
I loosened up the two bolts holding the master cylinder to the hydroboost and pulled the master cylinder ¾ of an inch forwards.
The brakes were still dragging, this eliminated the hydroboost as being the culprit. It also eliminated anything to do with the pedal, stopswitch and anything else rearwards of the master cylinder.
The next step was to loosen the front brake line from the master cylinder, hey presto!, it came out under pressure and the front brakes were no longer dragging.
$44 for a new master cylinder, problem solved.
Thanks again everyone for all of the good advice, this just proves what a great resource Steel Soldiers can be.
-Sarge

 

[Sarge]

I don't know why that posted twice, my mouse finger must be getting jittery in my old age!
Although I said thank you to everyone, I especially wanted to personnaly thank GreenBull because his advice was right on the money!
-Sarge

 

[GreenBull]

Hey Sarge, you are welcome! I'm happy you got it worked out and happy to be able to contribute to the SS community.

 

[lavarok]

Ok..so I had a similar issue on my M1031 after installing new calipers, pads, etc.

Turns out when I installed the inner brake pad, the adjusting clip was installed in such a way that it held the pad to the rotor instead of applying outward pressure to retract the caliper piston. This is the little clip that goes on the top of the inner brake pad.

The tab should be on the outside of the caliper mounting bracket. I had new clips and needed to bend them slightly for the fit. First time around, they were inside of the groove and kept that inner pad tight against the rotor.

Needless to say, I thought I had a master cylinder issue (seeing as everything else was new) until I tore it all back down and realized what I had done.

Pay close attention to this when reinstalling pads as it can lead you down a wild goose chase.

 

[Oldsouthernboy]

A point to also remember is that a old brake line can collapse on the inside causing a simular problem, So far you have not looked at the brake line from the caliper to the brake line connection. When I replaced my calipers and pads I did the brake lines also. These hoses may be 20 some years old. a lot cheaper the a master cylinder or a brake valve, and never hurts to know you have a good brake line to your calipers.

 

[Dave Kay]

Ok..so I had a similar issue on my M1031 after installing new calipers, pads, etc.

Turns out when I installed the inner brake pad, the adjusting clip was installed in such a way that it held the pad to the rotor instead of applying outward pressure to retract the caliper piston. This is the little clip that goes on the top of the inner brake pad.

The tab should be on the outside of the caliper mounting bracket. I had new clips and needed to bend them slightly for the fit. First time around, they were inside of the groove and kept that inner pad tight against the rotor.

Needless to say, I thought I had a master cylinder issue (seeing as everything else was new) until I tore it all back down and realized what I had done.

Pay close attention to this when reinstalling pads as it can lead you down a wild goose chase.

AYE! I'm with ya' on that little spring clip being installed proper like. Couple years ago bought a C3500 previously owned by some San Diego hillbillies and it had the Bendix brakes like our CUCV's. They had obviously done themselves a 'shade-tree' brake job in the recent past but this truck had lots of other problems from the git-go. First time I tried to slow to a stop the front end would shake a wobble so violently I was scared to drive over 30mph. Eventually I got to the brake work myself and sure enough; they had NO spring clips on either caliper/pad which caused the pads to drag and heat up and expand drag even worse and there's your problem... one of these days I'll get to the rears where it looks like they didn't bother replacing the inner axle seals becasue both sides leak gear oil into the brake drums, nice work eh?

 

[Asgar]

I have had my M1008 for about 12 years now. The original brakes failed 10? years ago due to bad rear hub seals, entire inside was gooed up in dusty gear oil. I did an entire brake job and new rear bearings. The spindles had wear grooves in them and the original style seal lips could not seal. Also the breather line at the pumpkin was full of mud wasp stuff, meaning when the axle got hot the oil was pressurized and that made the leak worse. I added window screen around the vent to keep the mud critters out. I used the modern two piece oil seal from a mid 90's 14 bolt application, it fit perfectly and since it 'seals inside itself' the grooved spindles made no difference. I don't have this part number any more so you need to check the dimensions but it looks like the NATIONAL 710568 seal, search around, don't trust me on this part number... 8K or so miles later i pulled the drums and not a drop of oil. I mention this because gear oil leaking onto the brake shoes can cause drag and grief as well. The better seal made a huge difference and the plugged vent is not obvious.

Ok, so fast forward to last Saturday.... On the way home one brake dragged and got the drum so hot I was worried it would catch fire. I pulled the drum the next day and I can say they can take the heat because everything was visually ok. Remember the seal, no gear oil in there so only brake dust and spiders. I thought it could be a residual pressure or stuck wheel cylinder but it was not the case. What I found is that the parking brake cables were working but not properly, so much drag between the cable and sheath that they were not releasing fully, keeping the brakes from adjusting correctly, pulled to right and even when 'fine' would squeal when coming to a stop. Trying to find these three cable was not easy for me, just looking up the K30 etc.. gave me mostly Dana70 parts and nothing matched up at the parts counter. On line at Rock Auto, Napa, Pepboys, Advanced Auto etc.. was also not successful just looking up the civy equivalent. I was successful when i did a part number search online, the three gm part numbers in the -30P manual did cross reference to the correct parking break cables. Using Rock Auto.... the Front e brake Pedal cable was 14053593 = DORMAN C93247; Passangers rear: 14064664 = DORMAN C93254; Driver rear: 14064663 = DORMAN C93253 and get the DORMAN 484221 parking brake cable connector, the stamped metal u piece. This group of parts cost $35 pulse $10 in shipping which is about what one cable was costing me in the walk in store. They are not made the same way as the original but fit perfectly.

When I put it all together I loosely adjusted the star adjuster. I put a little bore scope camera in the access hole and watched from the cab. I can tell you I saw the star adjuster happily spin one to two clicks each time I stepped on the service brake, at rest, or if I pushed down the e brake pedel, or rolled forward or rolled backward. Lots of opinions about how the adjuster works, ie parking brake or going backwards but I can tell you it cliked happily along just in normal stationary pumping or rolling forward as well. The end result of all this is really nice balanced brakes, no squealing, no burning / hot etc. It took me about 4 hours to do this cable swap. Remember to jack up one axle side 3 inches or so and almost no oil spills when you pull the brake drum / hub.

Hope this helps. I did not see a lot of parking break cables mentioned in the threads so I wanted to share this with you as well in case you had a single hot drum, pulling to the side for no reason, squealing when coming to a stop etc. Just sharing my experience this week, your parts buying preference and counter sales results may differ...

 

[M1911A1]

I have had my M1008 for about 12 years now. The original brakes failed 10? years ago due to bad rear hub seals, entire inside was gooed up in dusty gear oil. I did an entire brake job and new rear bearings. The spindles had wear grooves in them and the original style seal lips could not seal. Also the breather line at the pumpkin was full of mud wasp stuff, meaning when the axle got hot the oil was pressurized and that made the leak worse. I added window screen around the vent to keep the mud critters out. I used the modern two piece oil seal from a mid 90's 14 bolt application, it fit perfectly and since it 'seals inside itself' the grooved spindles made no difference. I don't have this part number any more so you need to check the dimensions but it looks like the NATIONAL 710568 seal, search around, don't trust me on this part number... 8K or so miles later i pulled the drums and not a drop of oil. I mention this because gear oil leaking onto the brake shoes can cause drag and grief as well. The better seal made a huge difference and the plugged vent is not obvious.

Ok, so fast forward to last Saturday.... On the way home one brake dragged and got the drum so hot I was worried it would catch fire. I pulled the drum the next day and I can say they can take the heat because everything was visually ok. Remember the seal, no gear oil in there so only brake dust and spiders. I thought it could be a residual pressure or stuck wheel cylinder but it was not the case. What I found is that the parking brake cables were working but not properly, so much drag between the cable and sheath that they were not releasing fully, keeping the brakes from adjusting correctly, pulled to right and even when 'fine' would squeal when coming to a stop. Trying to find these three cable was not easy for me, just looking up the K30 etc.. gave me mostly Dana70 parts and nothing matched up at the parts counter. On line at Rock Auto, Napa, Pepboys, Advanced Auto etc.. was also not successful just looking up the civy equivalent. I was successful when i did a part number search online, the three gm part numbers in the -30P manual did cross reference to the correct parking break cables. Using Rock Auto.... the Front e brake Pedal cable was 14053593 = DORMAN C93247; Passangers rear: 14064664 = DORMAN C93254; Driver rear: 14064663 = DORMAN C93253 and get the DORMAN 484221 parking brake cable connector, the stamped metal u piece. This group of parts cost $35 pulse $10 in shipping which is about what one cable was costing me in the walk in store. They are not made the same way as the original but fit perfectly.

When I put it all together I loosely adjusted the star adjuster. I put a little bore scope camera in the access hole and watched from the cab. I can tell you I saw the star adjuster happily spin one to two clicks each time I stepped on the service brake, at rest, or if I pushed down the e brake pedel, or rolled forward or rolled backward. Lots of opinions about how the adjuster works, ie parking brake or going backwards but I can tell you it cliked happily along just in normal stationary pumping or rolling forward as well. The end result of all this is really nice balanced brakes, no squealing, no burning / hot etc. It took me about 4 hours to do this cable swap. Remember to jack up one axle side 3 inches or so and almost no oil spills when you pull the brake drum / hub.

Hope this helps. I did not see a lot of parking break cables mentioned in the threads so I wanted to share this with you as well in case you had a single hot drum, pulling to the side for no reason, squealing when coming to a stop etc. Just sharing my experience this week, your parts buying preference and counter sales results may differ...

I was having a problem with the right rear shoes dragging. Much the same as you described. After reading your post I ordered and installed the parts you listed. It seems to have solved the problem. Thanks for listing PNs. Very helpful.


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