Front brakes dragging 1988 k2500

[Second Series]

1988 K2500 six lug. RWAL brake system. Brakes are dragging on the front. The calipers are new. The master and booster check good. I had to hammer on the calipers to get them into the bracket. Do the calipers need to be free in the bracket? It looks like I need to file the calipers so they have some room to move, but I’m looking for some input here.

[mingoman]

I mentioned this in your other post, but I'll throw my thoughts here to make sure you see it.
I'd replace the rubber hose going from the hard line to the caliper. They're known for separating on the inside and letting fluid go to the caliper, but not back very fast. I've had two that I'd swore were the caliper that turned out being the hose.

[Second Series]

Thanks for the reply! I had read about the hoses going bad, and when I last drove it and the wheels got hot, I cracked open the bleeders. The fluid did not squirt out, so that made me suspect the calipers. I’m not sure if that is a consistent test for bad hoses, one bad hose may act different from another? I think the problem was that I jammed the calipers on the brackets. I have never ground down a caliper to make it fit, just hammer it in place. I haven’t done many and this is the first time I noticed a problem. Last night I ground off some so they are free from the bracket. I’ll know for sure if that fixed it when I take it for a drive.

[61_FL_Apache]

I 2nd the rubber hose replacement. They are cheap and usually the culprit on older trucks.

I had that issue on a 79 Silverado.

[Second Series]

Is there a test to determine if the hose is the culprit? I had the front end on jack stands, opened the bleeder and had a hard time turning the wheel. That tells me the caliper was jammed, but it doesn’t rule out the hose. I thought the test for the hose was that if when you open the line by the master and fluid doesn't squirt out, open the bleeder, fluid squirts out would point to a restriction in the line?

[mingoman]

Originally Posted by Second Series

Is there a test to determine if the hose is the culprit? I had the front end on jack stands, opened the bleeder and had a hard time turning the wheel. That tells me the caliper was jammed, but it doesn’t rule out the hose. I thought the test for the hose was that if when you open the line by the master and fluid doesn't squirt out, open the bleeder, fluid squirts out would point to a restriction in the line?

May be the caliper. The ones I did would free up when I opened the bleeder.

[Mr_Rich]

Originally Posted by Second Series

1988 K2500 six lug. RWAL brake system. Brakes are dragging on the front. The calipers are new. The master and booster check good. I had to hammer on the calipers to get them into the bracket. Do the calipers need to be free in the bracket? It looks like I need to file the calipers so they have some room to move, but I’m looking for some input here.

The calipers should slide through the bracket freely. That could be part of a problem. My truck will be thirty years old (of ownership too...) and I've replaced the calipers and went with stainless braided brake lines on the front and rear in the last ten to fifteen years myself.

[Killer Bee]

the 'flapper' hose symptom you mention is not always consistent which can make it difficult to diagnose..

also not always easy to see even while looking through a hydraulic hose, may need some fluid force to make it show its butt..

as already recommended, just replace them anyways if old and suspect, cheap insurance from a brake failure..

as for the calipers, they absolutely have to move freely on the brackets as they are friction release..

if you still have the old ones, fit one in for comparison and you might find your culprit there..

that's a good start, keep us posted and good luck!

[special-K]

Originally Posted by Second Series

Is there a test to determine if the hose is the culprit?

Yes. Replace the hose (I'd do both) and see if that fixes it.

[Second Series]

I drove the truck on a few errands yesterday and had no problems with the brakes. If the brakes drag again, I'll replace the hoses. I used a sanding disk to grind the calipers, and put some silicon grease on the sliders.