Truck brakes

Rowski · Oct 8, 2000

No brake squeal at all. The severe duty pads have better grip and don't fade (when getting hot) like the OE ones. The OE pads were brittle due to the heat. The SD ones are supposed to be resistant to breaking down in the heat. The brake do get hotter than hot, like smoking smelly hot. I still think the rear brakes are not active enough.

The seal that went bad was the front differential axle seal not the rotor hub seal. This seal went bad due to mud in the axle tube. That spring went on a call to pull out a car stuck in the spring thaw mud. Got out of the truck to look over the situation. Went to go back to the truck and the front end (locking hubs) were in the mud /w3tcompact/icons/shocked.gif. Tried backing up no luck. But with 2 8000lb winches, 150' of cable on each winch, extendable boom, and snatch blocks it not to hard to stay stuck /w3tcompact/icons/wink.gif.

The cracked rotor was a suprise because I really didn't notice it driving (scary).

"But I know I'm not telling you anything that you don't already know and haven't already gone through"
Not a problem many heads thinking together are better than one frustrated one and get a lot more done too.

Derek

gordon · Oct 8, 2000

See what I get for assuming on which seal went bad and why. I believe your on the right track about the rear brakes not being active enough. But I'll ask the guys at the shop tomorrow and see what they think.

Derek I will say this though and I do know this for sure. Some of their replies might not be so nice Almost all the techs are GM lovers and Ford haters./w3tcompact/icons/smile.gif But we do warr. work on both so I'll see if I can get you a decent answer.
Gordon

scruffy · Oct 9, 2000

Bird, Derek, I don't remember the name (senior moment here), but there is a block that limits (or regulates) the pressure of the brake fluid distributed to the front and rear brake cylinders of a vehicle. The amount of pressure is dependant upon the total breaking surface, weight of vehicle, tire size, etc of each model. Ford should have the specs for the block, and it may become necessary to run a comparitive test of the pressure output from said block.
It is possible that the wrong one was installed at the factory.

Rowski · Oct 9, 2000

I believe that it is called a proportioning valve. I pretty sure the truck does not have one because it has rear anti-lock brakes. Basically it is supposed to work better. But you may be right that something may have not been right at the factory during assembly.

Derek

Bird · Oct 9, 2000

I've not kept up with working on a lot of this modern equipment, but if there's no proportioning valve and the truck has anti-lock brakes, it makes me wonder if something's gone wrong with the anti-lock system that's not letting enough pressure go to the rear at any time. Have you tried standing on the brakes hard enough to see if you get the pulsing that anti-lock brakes cause?

Bird

geneP · Oct 9, 2000

Derek, before I retired I was responsible for the fleet for a utility company. We had many problems with the HD 3/4 ton Ford trucks' brakes. The symptoms didn't usually appear until a rain came after a dry spell. The the drivers would report putting on the brakes, and the fronts would lock up and the truck would slide through an intersection. The dealership finally told us the the composition of the brake shoes that they had gone to when asbestos was banned from them would tend to cake up in the drums and not sift out. The dust acted similar to talcum powder and reduced the friction. The cure (temporary) was to remove the drums, clean out the powder, and assure that the shoes were adjusted correctly. As long as the pavement was dry, the traction on the front tires could stop the truck ok. Disk pad life was also short.

gordon · Oct 9, 2000

Derek I asked the braintrust at work today and nothing good to help you. Yes the rears are not working properly and a few things could come into play. Glazing, the abs system itself, master cyl, fluid blockage for one reason or another, or as Gene already said dust build up. Sorry nothing that anyone else could put a finger on. There is no supposed to be no TSB on those brakes. The service manager looked it up for me. Will look into it further Mondays are always a Zoo at the shop.
Or the bottom line another good cocktail napkin design from Ford. It sure looked good the the engineers at happy hour so they brought the napkin in the next day and presto the reason for so many TSBs from Ford.
Gordon

Rowski · Oct 9, 2000

Thanks geneP. I have run across that before and I think Ford even has a TSB for that. I have run across this on cars also. It has been a year since the drums have been off. It may add to my situation. I will be putting on the snow tires this month and will pull the drums off then. I do know they are adjusted properly done it twice this year. Thanks again for the info.

Derek

Rowski · Oct 9, 2000

Glazing
Will remove the drums and check when the snow tires go on this month.

ABS system
It is working properly. Usually with this style ABS system it will not effect normal braking only in anti lock mode. But it is defenitly a possibility.

Master Cylinder
Very good possiblity.

I have a data base system for service and repair info (ALLDATA). I get TSB also but the nwe ones are delayed by 3 to 4 months. I have checked then too with not luck. Even read most of them to see if I could even get a little info out of them, no luck.

I don't favor any of the big three truck makers. I just went with the Ford because at the time it was the only truck with a good front end (leaf springs-> solid axle) that can handle a 9' Fisher plow. As far as # of TSB's Dodge and Chevy got just as many maybe just not with brakes /w3tcompact/icons/wink.gif.

Be honest how hard did they laugh anyways? /w3tcompact/icons/laugh.gif

Many thanks. Let me know if I can help out with some shop info someday.

Derek

gordon · Oct 9, 2000

I had to rib you about the Ford, you know how that goes don't you. /w3tcompact/icons/smile.gif

At first yes they said and your point is then I explained that you were a Tech. and they all got real serious real quick---One Tech helping another out of jam is alot like this board and more times than not there is strengh in numbers. But sorry nothing that I could really help you without having the truck at our shop.

A plow truck sure takes some abuse thats for sure reguardless what make of truck. Around here we don't get a whole bunch of snow but when we do it's a money maker for me and the tractor.
Gordon