Brakes

[Markinter]

I'm loosing brake fluid somewhere.

The last day I drove my truck I noticed the pedal was low so I checked the fluid level and yes it was real low. I didn't drive it for a few days and the pedal went to the floor and the brake pressure alarm went off. I just put more fluid in and pumped the pedal and the pressure isn't coming back up so I'm assuming I need to bleed the air out. I looked around underneath the truck and I can't see any leaks. I had the rear brakes completely done last fall.

Any ideas on what to check and tips on bleeding the brakes? I have disc brakes all around. Rears have new rotors and seals and calipers.

 

[Markinter]

Update

Well I dug out the manual (doh!) and gravity bled the brakes and restored pressure. There is quite a bit of old crudded up oil around the master cylinder which I'm about to steam clean off. I'm going to keep my eye on levels and check for leaks once things are cleaned up, but so far so good.

 

[Duke]

Wait a minute, you mean you have hydraulic brakes? The ones with the brake pot booster?

 

[Markinter]

Yep all wheel disc brakes with the electric back up booster. Is that good or bad?

 

[Duke]

It's not bad. My personal preference is air brakes, but if you have hydraulic brakes, at least you have disc-hydraulic. Sounds like your booster my be shot. I had a S-series with the booster and I had to replace mine, it wasn't very expensive, though.

 

[Markinter]

Looks like I need a new master cylinder. I steam cleaned everything off and there is a nice drip coming between the M/C and the booster. A new M/C goes between $100-$200 I think. Service dept says it's more than likely the M/C.
Could be worse

Update! It was worse $300 I'm putting the new one on now and there was rusty cruddy slime in between m/c and booster. I told the wife at least were not paying $75 per hr to have it done for us, she still isn't happy .
Wait till I call her to pick up some brake fluid on the way home

 

[Markinter]

Bled the brakes and the fluid that came out looked like thick tea! It didn't taste like tea though so I didn't have a second cup.

 

[nevrenufhp]

I thought you told me it was already changed not too long ago. That's why there was peeling paint all uderneath the M/C. I should've went with my instinct & told you anyways, the fluid looked too fresh to me.

 

[Duke]

Bled the brakes and the fluid that came out looked like thick tea! It didn't taste like tea though so I didn't have a second cup.

How are the brakes? Are we happy campers once again?

 

[Markinter]

I had the rear brakes done (discs/ calipers) both sides in Grand Jct Colorado. I waited to see where the fluid was leaking from after I steam cleaned it. I waited and it got progressively worse, not smart of me.

The brakes are working great and from other post I've read it's hard to get the fluid clear even using a pressure bleeder. I ran 3 qrts through the lines and it's still not clear, but it is better.

I is a happy camper once again!

 

[Pacific]

Its pretty hard to get clean brake fluid through out the system unless you change all your brake lines which is a big job. The worst thing is old brake fluid that has absorbed lots of water you have to remember brake fluid is hydroscopic (sp) it sucks up water like a sponge.

The problem with that is it lowers the boiling point of the fluid so when you get the brakes smoking hot the brake fluid starts to boil and evapourate.

When you have a truck with 4wheel disk brakes like some internationals come with you need to keep the juice clean and fresh. The trucks with the 4wheeldisk brakes do stop pretty good they also produce abit of heat.

I'am surprised the truck doesn't have hydroboost over vacuum the last International 5 ton I worked on it had 4wheeldisk I can't remember if it was on vac boost or hydroboost.

If I had the choice it would be air S cams they are the simplest and most powerfull the only flaw is you need to know how to adjust your brakes and willing to crawl under your truck everyday to-do it.

 

[Markinter]

I have the Hydro-Max brake booster with the split hydraulic brake system with the EHP (electric hydraulic pump) reserve system. I'm going to flush more of the old brake fluid out with the Dot 3 and then add some higher boiling point fluid in.

thanks for the replies, Mark

 

[dozer]

Yup, once I drove air-brakes, I never wanted to get hydraulics again...

But the legal situation is so cloudy, that for a non-CDL like myself, the only way to avoid harassment is to go hydraulic, and with a door-tag that says 26K gvw or less.

I've been down to DMV and asked specifically if I needed an air-brake endorsement to drive an AB truck at 26K or under; and they said NO. However, the bears and DOT/weighstations don't seem to follow the same laws. Friends of mine have been actually red-tagged and walked home. So if I'm stuck with hydraulics, then I really do want the 4-wheel discs.

A guy dropped off an engine for me the other day, and altho he does have a CDL and other trucks, he was using a 1986 IHC 1900 with the discs; and he had nothing but praise for them. Said they stopped as good as AB and had zero fade even on 5 mile downgrades. Damn nice-looking rig, inside and out. Hope I can find one...and can afford it when I do...

 

[Sbrem]

Yup, once I drove air-brakes, I never wanted to get hydraulics again...

But the legal situation is so cloudy, that for a non-CDL like myself, the only way to avoid harassment is to go hydraulic, and with a door-tag that says 26K gvw or less.

I've been down to DMV and asked specifically if I needed an air-brake endorsement to drive an AB truck at 26K or under; and they said NO. However, the bears and DOT/weighstations don't seem to follow the same laws. Friends of mine have been actually red-tagged and walked home. So if I'm stuck with hydraulics, then I really do want the 4-wheel discs.

I have my CDL so it doesn't matter to me one way or the other, but it does seem like you get a different answer to that question depending on who you ask. A friend of mine asked a DOT officer and he said as long as the truck is 26k or under no CDL needed. But I have also heard people say you do ned one. Why not just get your CDL and then there would be no issues at all?

Stephen

 

[nevrenufhp]

I was surprised when I saw Mark's front rotors when the engine's timing got done. Them things are huge! Had to be about 16-18" in diameter! The calipers looked like they were a 2 piston floater like on an older F350, but about 30 pounds heavier. I love air brakes too, but I'd have faith in this setup.

Mark, you sure you dont want to trade straight across for my Dodge?