Help! All 4 brake drums smoking hot, fade, etc!

[The_Handier_Man1]

From: ClydesdaleKevin  (Original Message)
Sent: 11/29/2005 6:30 PM

Help!  what in the world is wrong with my brakes?  We made it to Virginia Beach with no problems, and even rode to and from the campground to the Christmas show with no problems all weekend.  Leaving Virginia Beach for Richmond, we noticed the brakes squealing a bit, but thats not too abnormal when applied.  And I didn't notice any brake fade or anything.

Then, driving on I-64 West towards Richmond, right around the Yorktown exits, I started to smell hot brakes/brake fluid.  At first I didn't think anything of it, just figured it was one of those roadside smells you smell from other traffic.  THEN I started to get brake drag!  The engine started to labor, and the next exit was 1 mile away!  I actually made it to the exit, and then off the exit, although I had to shift into 1st once I hit the ramp!  The ramp ended at a busy road, and I couldn't merge left into heavy traffic.  Luckily there was a bit of acceleration lane in front of me.  At this time, I still had some brakes, although they were heavily faded from the heat.  The acceleration lane was coming to an end, and on my left was a Wide Load modular home!  In front of me, walking in the brake down/pull over/shoulder of the road was a black dude talking on the cell phone, totally unaware that a classic RV was about to be his demise!!!

I honked the horn, and the black dude never even looked up from his cell phone!  I APE STOMPED the brakes, and they LET GO completely!  Right to the floor!  Thankfully, the Wide Load rig had passed me, and the pickup driver behind him noticed my dilemma, and my smoking brakes, and allowed me in.  There was a very wide pull off on the shoulder right past the hapless black dude, who STILL didn't realize he had almost been run over!

I slowed to to a halt, and got out.

ALL FOUR drums were smoking!  Too hot to touch any of them!  I decided to let them cool for a couple of hours before attempting to hit the road again, thinking that it was some sort of fluke, since, if you remember from my past posts, I had similar brake/heat/fade symptoms some 3000 miles ago that resolved themselves, and I had dismissed them.

While waiting, I checked the brake fluid.  The rear chamber on the master cylinder looked a little bit low, but only by a millimeter or two compared to the front.  I topped it up.  I looked at all the brake lines, and didn't see any wet spots or areas. I inspected the front hoses, and while dryrotted a bit, they weren't leaking. 

Then, I had my wife Patti pump the brake pedal continuously while I checked each drum on all four wheels.  There was no fluid coming from any wheel that was visible.

So, two hours later, I checked the pedal, and it was firm again...but went lower than usual.  Only 30 miles to go to the campground at the Richmond Speedway, so I decide to attempt it.  I made it there, with the following symptoms:

Brakes are obviously VERY messed up, and very dangerous.  They aren't dragging anymore and didn't get hot the last 30 miles, but I have to drive the pedal all the way to the floor to stop, and then some!  I have to pump them a bit to get enough pedal to fully stop!  Most of my slowing down was done via the parking brake and shifting into first...it was a slow ride to Richmond Speedway!

Long story short, we made it to the campground without incident or accident, but extremely stressed out!...lol

So, what could be causing this?

Obviously I blew out a line or a wheel cylinder or something when I stomped the brakes, but I can't find the culprit...Looks like I might have to pull a wheel or four!  But what is causing the occasional locking up of all four wheels, making all four wheels drag?  If it was one wheel, I'd know the answer right away, and fix that one wheel...but all four?  Master cylinder problem?  Brake booster/valve problem?

And remember, the Ark doesn't sit.  She's always on the go, and always on the road, and while I had these symtoms when I first bought her, they went away, and haven't returned for thousands of miles!  She has new brake lines, and when I bought her I removed the front drums, and the shoes and hardware looked relatively new.  There are many shiney new brake lines on her.

I'm stumped! 

There is an auto parts place right across the street from the campground, which is great!  My problem is that I don't have a jack that can lift the back axle off the ground...lol.  (Its on my shopping list when I can afford it).  Any ideas on how to fix this by next Monday, at least enough to make it to my next destination?

Kev



From: denison
Sent: 11/30/2005 9:42 AM

I would think that anything that affects all four wheels would have to be at the point where both parts of the dual brake system would combine; the master cylinder. The two halves also meet each other at the brake-warning-switch “T” fitting, which is what tells the red light on the dash to light up in the event one side of your brake system loses pressure. But this fitting is very reliable.
Anyway, my First Thought is that for some reason your brake pedal isnt getting completely released. This would prevent the piston inside the master cylinder from returning fully, and the compensating ports would not be opening. These are the tiny valves between the m.c. reservior and the bore of the m.c. They MUST be able to open each time you release the brake pedal. The heat from applying the brakes expands the fluid in the wheel cylinders, and forces a small amount of fluid back into the brake lines. If the compensating ports are not opening, the fluid cant escape back into the m.c. reservoir when you release the pedal, and pressure will build up. Therefore the brake shoes wont retract, causing more heat. More heat will expand the fluid more, and make the brakes drag worse.
When the brake fluid gets hot enough to boil, it will want to turn to a vapor, keeping the pressure on. The fluid will eventually bleed back into the reservoir, but it might take minutes or hours to do so. When everything has cooled, the “pocket” of vapor can still remain in the far regions of the brake system, like at the wheel cylinder(s). You would feel this as the brake pedal going a ways to the floor before the pocket of vapor was squeezed down. So, bleeding the brakes would hopefully get the brakes to come on normally in response to pedal movement.
The matter of those compensating ports not opening; there is supposed to be a slight amount of “play” in the pedal, before it begins to push the actuator piston into the m.c. It is possible that a shift in a piece of cruid has gotten into the way of the pedal fully releasing. You would have to examine both above and below the floor to see this. There is a grease fitting on the brake pedal pivot shaft too. You have to reach it from under the RV, and it isnt easy to get to.
And the compensating ports have to close, or there would be no brake pressure in the system!
I think there are what amount to “compensating ports” in the boosters. But a failure there would only affect one front wheel and 2 of the 4 shoes on the rear wheel. If both of your front drums where hot, such a failure would mean that both of your boosters went back at the same moment.
I don’t think so.
I doubt you will have to take the drums off â€" unless the heat damaged the wheel cylinders. This would show up as fluid loss, and streaks of it spraying down the inner sidewalls of the affected tires, maybe with some brake fade or grabbing. (The sidewall toward the centerline of the vehicle. In which case, you could install the “rebuild kits”, which include the new rubber cups, dust covers, and springs. The problem would be finding a source for them.
I will send you an email with my cell phone #. i am in Alexandria, will be driving past Richmond tomorrow before noon. Not in the Winny, in my van towing a car on a trailer.



From: denison
Sent: 11/30/2005 11:28 AM

And the problem with the compensating ports not being opened, is something you dont fix 'per se', with a new master cylinder. You fix it by either ensuring the brake pedal fully releases every time, or by adjusting the actuator rod so it doesnt quite touch the actuator piston in the master cylinder. The actuator rod is in two pieces, one threaded over the other, so its length is adjustable for the purpose. Its something I would remove the drivers side front wheel to reach.
On a vintage truck, I used bungee cords to pull the brake pedal back, until I could get a new brake return spring to install.



From: Slantsixness
Sent: 12/5/2005 9:29 AM

Kev and I managed (barely) to limp the Ark to my house in Fredericksburg, and as soon as Kev and Patti get up this morning (they haven't had much sleep last couple of days), Kev and I will tear into the brakes, and hopefully a couple other issues.

Hopefully we'll have an answer by this afternoon, before we get snowed on!!

Tom



From: denison
Sent: 12/5/2005 1:06 PM

I stopped at the Rich.Int. Raceway saturday a little before noon, and saw the Ark, but other than a barking dog inside, didnt see the Smiths. Were they inside working a show? Rather than worry the barking dog, I didnt crawl under it to look for leaking brake fluid
I am now in the Rio Grande valley again, having driven 2000 miles through slowy improving weather, and back to having access to the internet.
People here think it is chilly....Hah!!! It is about 60 degrees, sunny and breezy.
Amyway, we are eager to learn what the failure was or failures were. One of the big benefits of the CWM site is that we can then check for the same situation on our own Winnies. 



From: ClydesdaleKevin
Sent: 12/6/2005 11:22 AM

Thank you so much, Dave, for stopping by!  I am extremely grateful for all of the help all of you have given us, both in advice, and now in going out of your way for us.  Yes Dave, we were inside the buildings working the Christmas show.  Sorry we missed you!

Kev and Patti



From: ClydesdaleKevin
Sent: 12/10/2005 8:46 PM

We found the source of the actual brake fluid leak and the cause of the pedal going right to the floor!  One of the rear steel brake lines on the driver's side let go when I stomped the pedal!  We replaced both of them on that side since they were both pretty crusty.  The other side looked ok, so its good for now.  We also got the master cylinder removed without breaking any lines, and loosed all four rear bleeders without breaking or rounding them.  I still have to make sure I can get the hydrovac booster bleeders (there are 2 of them, one on each hydrovac cylinder) to break free without breaking or rounding off.  They are 7/16, so a socket works wonders!  Its going to be new wheel cylinders and a new master cylinder in the front, so there won't be a problem bleeding the front at all.

Kev



From: ClydesdaleKevin
Sent: 12/11/2005 6:55 PM

I'm going to post this as its own post after I type this, but we really REALLY need a source for wheel studs for five lug Budd wheels!  We were almost finished, and discovered that the wheel studs on the driver's side were stripped, and won't tighten!  Four out of five, stripped!  The shop that installed my tires must have done it.  Anyone know a source for five lug Budd wheel studs, hopefully a source I can get them quickly from?

Kev



From: hudsonmand
Sent: 12/11/2005 8:41 PM

call merrit truck parts in chicago ask for wheel and rim house