Vibration of rear drum brakes with warm weather.

[PTRWorkVan]

I'm stumped. My mecahnic is stumped. I have a 2011 Transit Connect, 135k miles. My mecahic had replaced the rear shoes last year, and since the replacement, I've had issues with the rear making noise. This only happens in the summer months, and when it's warm out. I had no issues in the winter. During medium to long trips in the city (a lot of stop and go) the rear shoes will feel like theres a low or uneven spot and pulse slightly to moderatly when stopping. I've initially replaced the shoes with a cheap set, and then a Motorcraft set after having this issue. We even went and replaced the drums to a Motorcraft brand as well, but still have the issue. The only way to prevent the pulsing (and scraping noise) is to slightly pull on the handbrake when stopping. We checked the tention of the handbrake, we triple (or more) checked the shoes, drums, alignment, and fit of everything, and we still can't figure it out.

 

I'm trying to get a list of things to check on when I go back, that way my mecahnic doesn't think I'm insane. I honestly don't know what else to check. I've searched the forum and have some ideas, but if anyone has any other ideas or something that worked for them, please let me know.

 

I've attached a clip of what it sounded like in July of 2019, summer months.

[Beta Don]

When installing new shoes in drum brakes, it's important to arc the new shoes to fit the drum, otherwise all sorts of nagging problems like you're experiencing can happen.  It's also a good idea to turn the drums so they are smooth before you arc the shoes to fit the drums.  Both these procedures used to be SOP at any good brake shop back when drum brakes were more common, but now that 95% of vehicles have disc brakes all around, it's not so easy to find a mechanic who knows much about drum brakes, let alone one who has the tools to turn the drums and arc the shoes to fit them.  Hope this helps you with your problems

 

Don

[G B L]

Do you have a picture of the brake assembly with the drum removed ? Finding a shop with arc grinding equipment and someone still willing to use it is a task.  If you have new shoes and new drums you should be able to get this right without grinding the shoes.

[mrtn]

Mine was also having regular drum wobble. Needed replacement more often than normal.

[PTRWorkVan]

On 4/24/2020 at 2:51 PM, Beta Don said:

When installing new shoes in drum brakes, it's important to arc the new shoes to fit the drum, otherwise all sorts of nagging problems like you're experiencing can happen.  It's also a good idea to turn the drums so they are smooth before you arc the shoes to fit the drums.  Both these procedures used to be SOP at any good brake shop back when drum brakes were more common, but now that 95% of vehicles have disc brakes all around, it's not so easy to find a mechanic who knows much about drum brakes, let alone one who has the tools to turn the drums and arc the shoes to fit them.  Hope this helps you with your problems

 

Don

Thank you Don, I'll check with my mechanic on Monday to see what hardware he has.

 

6 hours ago, G B L said:

Do you have a picture of the brake assembly with the drum removed ? Finding a shop with arc grinding equipment and someone still willing to use it is a task.  If you have new shoes and new drums you should be able to get this right without grinding the shoes.

I should be able to provide that Monday as well. The shoes and drums are probably 6 months old by now.

[PTRWorkVan]

I managed to get pictures last week and I wanted to upload them sooner but this forum was acting up and wouldn’t load.

 

My mechanic grinded off the edges of the shoes, hoping to quiet them up to no avail. I drove the van this morning for a few hours and it was still making the noise when stopping. It sounds like it only comes from the rear passenger side, but both sides look similar. I’ve attached both passenger and driver shoe and drum. 

[Don Ridley]

Question/suggestion:

Could a bad bearing cause this symptom? The rear axles don't see stress against the bearing except when braking due to front wheel drive. Maybe the sound is coming from a bearing?

[G B L]

Carefully have some one step on the brakes with the drum off {gently very gently } and watch the action of the shoes . See which one moves first , If the effort to move one shoe is  more than the other then when they apply you could get  noise and a shudder before the pressure on the  shoes equalizes. 

You can check the wheel bearing with the drum off it should not have any wobble and not sound like a dry roller skate .

Thanks for the pictures keep the info coming

[Beta Don]

20 hours ago, Don Ridley said:

Question/suggestion:

Could a bad bearing cause this symptom? The rear axles don't see stress against the bearing except when braking due to front wheel drive. Maybe the sound is coming from a bearing?

 

You may very well be on to something there!  My experience with rear drum brakes has always been with RWD vehicles which have long axles with heavy duty bearings which run in an oil bath  -  Rear bearing failures are fairly rare.  In this case with a FWD vehicle which doesn't have long rear axles (I assume they're stubby little things with a bearing on either end?) virtually any play in the rear bearings could cause a very slight wobble which might exhibit the symptoms he's experiencing.  It would be a very good idea to carefully examine the rear bearings and if they appear less than perfect in any way, change them.  If he has a high mileage TC, it might be worth changing them just for GP.  That just might solve the problem

 

Don

[G B L]

This is the rear hub assembly on a gen 1 TC it gets replaced as a unit. An easy job . with the drum off the bearing is very easy to check.

. 

[PTRWorkVan]

Thanks for the replies guys, I really do appreciate it. I’m going to order the rear hub assemblies for each side and install them. My mechanic said they visually looked okay, but since it is a high milage TC, I want to replace them anyway since they are inexpensive. I'll let you know the outcome once they are fitted.

[PTRWorkVan]

So just a month status update. I replaced the rear hub and it fixed the issue of the noise. That was until today. It’s about 80 degrees where I’m at in New Jersey and they are making just as much noise as before.

 

Once again, I appreciate everyone’s advice, but at this point, I’ve spend too much time and effort trying to fix this issue, and I’m just going to leave it be. 

[G B L]

 I wish i could get a ride in the tc, there has to be an answer.  if  more information please let us know.