Intermittent Brake Dragging After Shoes and Drums Replace

check your flex hoses for blockage! peace!

I have had this happen to me in the past. The two things that caused it were:

1. The rubber brake hose had gone bad, swelled and acted effectively like a check valve allowing fluid to go into the brake, but not back out. Changing the hose fixed that problem.

2. The emergency brake mechanism failed on a rear disc brake caliper internal to the caliper itself. This caused the return mechanism to only retract the brake partially, thus causing the brake to drag. Replaced the bad caliper and the problem was solved. One of the indicators is that the handbrake has less resistance in it when pulled and more travel than prior to the problem showing up.

As well stated before check the hose(s) to the rear. If I might suggest. Get it on jack stands with the wheels off the ground. Run the engine and hit the brakes hard. Release the brakes and check for dragging wheel(s) If there is only one rear brake hose, the both rear wheels should be dragging the same. If two rear hoses they can drag independently of each other. One other thing to check for is the free play in the the master cylinder. If the free play adjustment was loose, it can take up all the free play and then start to "pre-load " the master. That can cause the master cylinder to keep the return port in the master blocked allowing pressure to remain in the rear cylinders. Good luck. If in doubt, dump all the hoses for new ones.

I neglected to pass this information about checking the hose(s). After hitting the brake hard, if the wheel is still locked, or dragging, the test is to open the bleeder valve on the dragging wheel. If that releases the brake drag the hose was holding pressure or the master cylinder was holding pressure. To test the master cylinder, loosen the free play at the pedal pivot. If there is no adjustment there, you can TEMPORALLY loosen the master cylinder from the booster, and retest. If that does not release the brake, look elsewhere.

Just a note:

Make sure the drive wheels are the ones up in the air. If your working on drum brakes (which are usually the rear) and you car is front wheel drive then you have a big problem with this suggestion.

Now if the suggestion is for all four wheels to be off the ground for this test then thats a different story however I have seen a car fall off jackstands doing a procedure like this just from the sudden change of momentum. Disclaimer: The car was on dirt not cement and it wasn't me, it was my none mechanical know it all brother LOL. And yes there was an I told you so involved.

Always remember safety first. It's better to use blocks under the frame for a procedure like this or very high quality jack stands and make sure the surface is hard and level.

For safety's sake I was not intending for the wheels to be driven by the engine. I only wanted the engine running for the purpose of generating sufficient vacuum to cause high brake line pressure. Thank you for bringing my error to light. Please do not put the transmission in gear. Be safe.

Was it done by a qualified mechanic? On drum brakes there are leading and lagging shoes and they are not interchangeable! There is also a spring that keeps the shoes retracted, it is not optional...

The rear shoes can be adjusted TOO CLOSE. This causes the shoes to rub & heat up. They expand, causing additional drag. This happened on my first cat when I replaced the shoes (4 wheel drums!). Fortunately for me our local friendly mechanic explained & set me straight.

I have had a similar situation on a '66 Mustang with high mileage. New shoes, drums, hoses, emergency cables and master cylinder. Turned out to be the backing plate rubbing points were grooved and caused the new shoes to hang up and not fully retract. It actually caused the shoes to wear crooked. After hunting through all the catalogues and Fords "GREEN SHEET" or "GREEN BOOK" (a special parts division for NOS parts) and not coming up with anything affordable, I filled the grooves with a MIG welder and filed it down. Problem solved!

This looks like a good place to start.

He says the condition did not exist before the changes, so that seems to eliminate things like hoses...and implicate the "brake job" itself. So the starting point would be to go back, inspect, look for what was not done, or corrected, correctly. Examples:

Return springs are cheap and should be changed with drums whatever the appearance of "feel" of old springs.

Lubrication points and surfaces (such as back plate) should be cleaned and re-lubricated with proper grease.

So the plate defect/shoe hanging idea is a good one...a good place to check.

If inspection only fails to turn up obvious culprit, it could also be that the condition will disappear with wear-in of shoes and drums. Since it's a student car, though, be careful to monitor that the situation is not getting worse.

Sounds like your adjuster was not turned back far enough or the threads inside the adjuster are dirty. When you put it back togeather before letting it down off the jack apply the foot brake several times and release the the same with the hand brake. Have someone spin the wheel before you hit the brakes if you can.

Then spin the wheel and listen for any grind.

Sometime a brake spring can also be weak from long term use then being sprung some in the removal process. The shoes then are not pulled back properly and allow drag.

Brakeline as a check valve happened to my '98 Breeze. If you let it continue, you'll "Hotspot" the drum and even if you replace new line and pads you may have an uneven "Grabbing". Be prepared to replace all hardware, pads, drum after you figure out what was the cause. Look for the discoloration in the drum wear surface for those nice rainbow colors. Rotsa Ruck !!!

One thought I haven't seen stated in this thread. That car has self-adjusting rear brakes. You can try backing up and firmly braking to force the adjustment. Several tries may (or may not) make a difference if it's just an adjustment problem.

There are several good options that have been mentioned. One other possibility is a problem with wear or contamination in the wheel cylinder causing it to stick or get cocked in the bore and not allowing full release of one of the brake shoes. This can cause an intermittant dragging problem. To check it disassemble the cylinder, look for contaminants or particles as you disassemble. Check the bore and piston for grooves, gouges and pits. The piston should move inside the bore smoothly with little or no wobble. Replace the wheel cylinders if you find problems with any of these areas. If there is any discoloration in your brake fluid or it looks cloudy the system should be flushed and new fluid installed.

Remember to flush your brake system every two years with fresh fluid because most brake fluids (exception silicone based DOT5) are hygroscopic and will pick up moisture. That moisture then rusts brake components like wheel cylinders or calipers and can cause binding of the components such that the brake friction linings are not fully released when the pressure is released. My 2¢.

P.S. Don't use DOT5 fluids unless specified because it is not compatible with some of the brake components designed for DOT3 or DOT4 fluids.

All valid suggestions so far, when you checked the hand brake operation was that with the drums off? These types of brakes are prone to the lever passing through the drum back plate seizing up, a few well chosen blows with a club hammer usually fixes this.

Did you chamfer the leading edge of the new shoes? This helps prevent the shoes from sticking to the drum.

to find which brake is hanging,start out when vehicle has sat and is cool.drive about a mile and pull over.go around each wheel and put the back of your hand to the wheel area.the one that's hanging will be hotter than the others.I agree that the emerg. brake cable could be stuck inside it's sheath. pull cable will have excessive slack in it.a lot of people including me while doing front brakes,drop the caliper during removal,while the line is still hooked.this can damage the rubber inside.. like the guy said,, making it act like a one way valve.

<...Intermittent Brake Dragging...> could be a symptom of a worn wheel bearing, especially in a car that is now over 25 years old. Most [work]shops have the ability to detect and replace; take it to a professional who knows what to do.

In the UK, a worn wheel bearing would be highlit as a fault during the vehicle's annual MoT Test; it is unlawful to use a vehicle on the public roads there without a current certificate except for the purpose of getting to and returning from an approved MoT test centre.