7.5- What damage could i have done

[fireguy12117]

My dumb a$$ didnt put 2 and 2 together when i had to fill up brake fluid recently and when i braked sudden and hard why the truck got squirly...

when putting on the snow tires, i checked out the rear brakes by pulling the drums to find brake fluid absolutely covering the pass. side brakes. it was a more or less obvious fix, but what damage could i have dont to the outter axle brearing? i used a needle fitting to try to pump some grease back behind the seal, but im sure some brake fluid got back there.

how good are those seals? is this something that i need to immediatly get out there and pull the axle shaft? can i just pump more grease in there?

ive also noticed a hum that i couldnt isolate. i eliminated the front bearing play, and play in the u-joints, and about the only other thing i can think is that bearing...

 

[AllanD]

Uhhhh... the rear axle bearings aren't greased.

That seal is there to keep the gear oil in the axle.

Brake fluid going in? I really doubt it.

Gear oil comming out? OH yeah....
BTW, if the axle seal is bad it's a SYMPTOM, not the cause of the problem....

Usually when the seal goes it's because the bearing has literally
cut a groove in the axle shaft and the shaft is wallowing around on the groove.



AD

 

[fireguy12117]

well poop...

thats good information. the seal itself looked fine once i cleaned the gunk off that area. so what the heck did i do by shooting some heavy grease back there...i guess im not worried much about that.

the only play on the outter axle plate where the studs are, was in and out play, no rotational play like a bearing loosening up inside. i deal with 3phase motors a LOT and we loose them to bearings all the time so im guessing the feeling would be the same.

so really there is nothing to be done here eh? maybe check fluid levels in the pig just to do it...

this all spawned from a co-working telling a story where a brake componant did fail and he did have to pull the shaft to repack the bearing. i beleive it was on a probe. since ive never had an axle apart, i just didnt realize how they are put together.

 

[Natedog]

You didn't hurt it from the sound of it all...AllanD is correct you probably need a new axle shaft, bearing and seal on that side. I'd pull the other axle to check it too. My passenger side axle wore out like that but not as bad. Driver's side is still fine.

 

[fireguy12117]

well i suppose the possibility exists, but its beyond a doubt that the brake was pissing fluid out of the cylinder and all over everything inside the drum. i can pull the tire this weekend and see if i have fresh fluid, but the clyinder was definatly leaking and needed replacing. ill have to dig further this weekend. i hate working in the cold...

 

[MAKG]

He MAY need a new axleshaft and bearing.

The major question to ask first is, did the brake PEDAL feel soft while the back end was "squirrely?" Did the BRAKE light come on? If the answer to either is yes, this is indeed a brake failure. If they are both no, it's probably the rear end. Unless you have synthetic gear oil, you can identify it by SMELL. Gear oil stinks. And it eats up brake shoes.

 

[fireguy12117]

after replacing the brake piston, or cylinder, or whatever you want to call it, there was night and day difference in the brakes. much more balance, smooth, with just the right firmness in the pedal- afterwards. up until i fixed the brake, it was a bit mushy, had to replace missing fluid...i could see fresh wet fluid on the actual piston plunger that pushed on the brake shoe, right around the rubber seal. when i grabbed it after taking the bolts out, fluid squirt out on me.

the rear was squirly when hitting a bump or hard braking because there was obvious unequal stopping force being applied on the rear axle. it acted a lot like spring hop. there was oil all over the shoe pads themselves, the small holes in the padding were caked with dirty oil you could see oil built up on the "trailing" edge of the pads...

i didnt get in there and huff the stuff (which ive done the smell test before. is it wrong that i like the smell of brake cleaner?). and no the brake light never came on i think because the level never got to drop low enough since when i did the oil change i refilled the reservoir. i had a pretty clear cut case of a bad brake, but it all comes down to making sure that the brake fluid didnt get behind the seal and eat away bearing grease. that seems to have been solved, so where i seem to be at is making sure the fluid level is good in the axle, and continue to monitor and try to isolate that hum. hell, it could be tires!

im at work, bored out of my mind, so thats why such a long reply, sorry!

oh yeah...im freakin out because im taking this truck from detroit to bangor after christmas...

 

[Explorin94]

You can buy a repair bearing if the axle is bad where the old axle bearing was. The repair bearing is about $22 at NAPA and is the bearing and seal in one.

 

[AllanD]

BTW, the way to check rear axle bearing is to check for radial play.

Mostly up and down.

AD

 

[MAKG]

From the description, it really does sound like the wheel cylinder puked. Though the BRAKE light should have been on (it's an unequal pressure from front to rear test, not a level test). Nevertheless, poor feel and missing fluid that was corrected by a wheel cylinder replacement strongly suggests a bad wheel cylinder....

I'd do Allan's test to be sure. It's easy.

 

[rickcdewitt]

You can buy a repair bearing if the axle is bad where the old axle bearing was. The repair bearing is about $22 at NAPA and is the bearing and seal in one.

they can be a b*t@h to put in(tight fit easy to get cockeyed) but they do work.

 

[Explorin94]

they can be a b*t@h to put in(tight fit easy to get cockeyed) but they do work.

Usually I destroy the old ones taking them out and use the old race to put the new ones into the axle. I use a long prybar to get the old ones out.

 

[rickcdewitt]

Usually I use the old race to put the new ones into the axle. .

good idea

 

[fireguy12117]

I did do Allans test the day i had it apart. Like I mentioned, I have to deal with hosed bearings all the time at work on motors, so I have an idea what I’m feeling for and there was no play on the shaft in any direction. I just haven’t noticed anything getting worse since redoing that brake, so I’m going to do a thorough once over before hitting the road in the potentially worst part of the country during the worst part of the year...