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Chevy C/K Series Maintenance and Repair
I have a 1990 K2500 Chevy pickup with RWAL.
I have had problems for quite sometime with the right rear wheel locking up when applying the brakes. I installed new rear shoes and it really compounded the problem. I then installed a new master cyl. & wheel cylinders and the problem still exists. Sometimes it feels as though the drum is warped as I get a vibration when applying the brakes but not always. I checked the drums and they are within .010 roundness. Is there any way to check the combination valve? This valve is pretty expensive and I hate to replace it and still have the same problem.
I have had problems for quite sometime with the right rear wheel locking up when applying the brakes. I installed new rear shoes and it really compounded the problem. I then installed a new master cyl. & wheel cylinders and the problem still exists. Sometimes it feels as though the drum is warped as I get a vibration when applying the brakes but not always. I checked the drums and they are within .010 roundness. Is there any way to check the combination valve? This valve is pretty expensive and I hate to replace it and still have the same problem.
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Dusty
Do you know that the left rear wheel brake is working correctly? Getting less pressure?
If one wheel locks and the other doesn't, the drive shaft will turn twice as fast.
If the sensor is on the drive shaft, it would see increased speed and apply some strange engineered logic control? It could be comparing front speed to rear speed and reduce braking to the slower of the two. If there was a weak/blocked pressure on one side, the problem could be exaggerated. How are those flex brake hoses?
I am still wondering about the combination valve,
(the proportioning part of it.
Many manufacturers with RWAL Brakes only use one sensor. Dodge uses an encoder (they call it the exicter ring) made out of steel internal with the differential and mount a sensor on the rear axle housing.
Since Dodge uses the GM-made American Axle on some of its trucks, I suspect yours is the same way.
So, I take back what I said earlier. You could have a pinched brake line on the side that isn't over-applying. If you've inspected everything at the rear brakes on both sides and everything looks good and operates static, then I think you'll find you have a bad hydraulic control unit (HCU) or ABS Control Computer. Since it is a GM product I think this HCU high on the suspect list. I've seen quite a few of them fail.
Good luck,
Dusty
MCMike: The tailights were known on the older trucks 1988 & up to corrode the curcuit board on lamp holder. I had same problem on my 88. You need to replace taillamp holder assembly with upgraded unit. The holder unscrews from the lense once you take the entire unit off truck. Another problem was that the lights would melt the lenses from the short which kept the lights on all the time.
Ray T.
If its your brake lights check the brake pedal sensor switch to see if its working properly, I had this problem once on a GM car.
If its your tails lights see the previous post.
Any idea what would cause these gauges to suddenly start acting act so strangely?
While I'm here, can anyone tell me if the lug bolt pattern on the C20 has changed over the last 35 years? I have a 1969 C20 camper conversion w/ step side long bed that has 68K original miles and all original equipment. Having original rims and hubcaps is great, but it makes for expensive tires. Living in Fairbanks, AK, I have considered for many years to get a set of winter rims that were more up to today's standards. The 16.5 rims make it difficult to find tires and when I do, they are expensive. I don't typically haul too heavy of loads in the winter other than the 900 lbs of sand to give me enough traction to stay on the road, so a rim/tire set wouldn't need to be capable of the load rating 'D' I use now.
Any suggestions?
Just thinking about it intuitively, it doesn't seem like tank pressure should negatively affect the flow of fuel to the engine - vacuum, yes, but pressure, no. But, with all the interconnected electronic gizmos and sensors on vehicles anymore, who can tell? You might check a repair manual for your rig's year to help figure out what systems are in place for evaporative control. I know that mine breathes through the gas cap, but newer ones probably try to internalize the evaporation to prevent fumes from escaping the vehicle. There's likely a block in the evaporative system somewhere and if you had some diagrams to help lead you through an inspection, you might find the culprit.
Good luck!
Just some thoughts.
I'm not sure, but just for clarity is this a negative pressure (vacuum) or a positive pressure?
All other things being correct, a clogged fuel filter will not cause the tank to "implode" because a clogged filter would stop the flow of fuel from going out of the tank.
Dusty
The only problem that I've had is at 93K the
autotrany trashed. Then at 103K the pump in the
transfer case wore a hole in the case. The steel
stop clip has since been enlarged.
GM stated that after 100K their design
fault was my problem.
The most that I've had on it is maybe 700lbs,
once or twice. Chevy said that because I didn't take it to a dealer, and it had over 100k on it, it
was my problem. My '91 s-15 has 135k on it and no trany problems.
Do you live in a warm climate? If you had never changed the tranny or diff fluid, then I can see why Chevy wouldn't want to warranty the repair/replacement costs after 100K, but if you had and could document that you had, then it is poor service on the mfg's part. I've seen worse though....
My father purchased an '01 Nissan Frontier new w/ all the goodies. He mostly uses it for commuting and as a tow-behind with his RV. at ~ 35,200 miles, one of the leaf springs on the rear left side broke, twisted about 10 degrees, and punctured the gas tank. While it was discovered almost immediately, they were on an RV trip about 1000 miles from home and headed home, so they decided just to move the spring back in place and duct tape in in position. They pulled the truck home and stopped at the dealer on their way to their house. When they pulled in at the dealer, the truck had 36,124 miles on it, but Nissan would NOT cover the nearly $1000 cost of replacing the tank and the leaf spring because it was out of warranty (3 year / 36K miles), even though the problem was almost assuredly a mfg defect, the part broke before the 36K mark, and it was far less than 3 years from the purchase date. Talk about cheap. That took the cake.
Joe
Good luck! If nothing else, replacing the AC Delco with a non-maintenance free unit will allow you to monitor fluid levels in the battery. If the level drops rapidly, the battery is likely being over-charged.
Joe
on distributor shaft. Had similar problem worked fine while idling in shop, put got erratic when driving.Reluctor starts to slip on shaft and trows spark timing off. just a suggestion. hope it helps
thanks, anthony.
thanks
Rob
The electrical flow must be regulated by a circuit or it would either melt the sheathing off wires or blow a fuse. Yet, if it drains your battery overnight, it must also be a fairly significant drain. Maybe your ignition switch is bad? It is not actually turning off, but instead is remaining in the "accessory" position even though the key/tumbler indicates it is off. I have this problem with my '69 Ford van sometimes (except that it sticks in the ON position and the engine will not cut either). On my van, it is not the ignition switch itself, and I have yet to isolate where the problem lies.
Anyway, I do not know if this is "any help" or not, but good luck with it!
There doesn't seem like any other reason that the pump would quit unless they were bad from square 1, which is doubtful...
-David
Thanks.