Cummins brake issue

[xjmarc]

Excuse my ignorance but I'm a bit clueless on brakes on diesels. So I went to load up this morning, got the trailer out in the street and put the jeep on it. Came back out with my cooler and such and cranked up the truck and it has an ABS light and Brake light on, doesn't even have ABS. Here's the fun part no brakes. Pedal goes to the floor with almost no resistance and it eventually stops but I had to use the hand control on my trailer controller to get it to stop. It's a 97 12 valve 2wd. Like I said I know nothing about this kind of system. Brake fluid is full although a little dark, guessing it's old. It has hoses running to the steering gear box and steering is fine.

 

[SHELBS44]

Sounds to me like either air in lines or internal bypassing master cylinder. Does it get hard when the engine is off? It's a hydro boost system since diesels don't have any vacuum. It uses the pressure from the steering to assist the brakes. U can clamp off one of the braided lines supply after the master cylinder then see if the pedal gets any harder. Try bleeding them first if that doesn't help you more than likely have a bad master cylinder. At least that's how it sounds if you have no leakage at any of the lines or wheel cylinders

 

[xjmarc]

Haven't seen any leakage but I'll check. Funny part is it was working fine then I turned it off and once I started it again, which it was a little hard to start like in winter, I had nothing. Running or not I have no pedal. About ready to get rid of it and find a newer 4wd with a short bed. Long bed is a pain in my back yard with the trailer.

 

[SHELBS44]

I got a dually I'll put u on :****: check your master cylinder first.

 

[Hudson1]

The front brake caliper pistons fall apart. Had this issue, also had the anti lock pump motor burn out. All on a 2000 3500 4x4.

 

[SHELBS44]

Don't believe his 97 has an anti lock pump since its non abs.

 

[KyTrash]

Check your brake lines behind the fuel tank, both my trucks have rusted and started leaking there. 95 and 99 . I have saw several do this.

 

[xjmarc]

I'm thinking it's not a leak since the master cylinder is full. Pass on the dually, hard enough parking this one and navigating my back yard. I'd love to replace it with a newer 4wd truck but to get one with 200k from the early 2000s still run 20k and I'm a poor boy.

 

[94xjsport94]

Naw... I find 94.5-97 DIT 7.3's in good shape from 6-12k and 99-03's in good shape from 10-15k a lot of the time.

 

[xjmarc]

Naw... I find 94.5-97 DIT 7.3's in good shape from 6-12k and 99-03's in good shape from 10-15k a lot of the time.

I had a 95 7.3 and it was the biggest piece of **** I've ever driven. Spent more time in the shop than on the road and it was brand new. It finally had a recall on the glow plugs but I didn't have it then.

 

[KyTrash]

Sounds like your hydro boost is going bad and I don't know how to check it.

 

[SHELBS44]

I'm not 100% it would be his hydro boost still say check master cylinder first but instead of trying to tell you step by step this will really help you let us know what you figure out or if you need any more help. Also I'm putting my dually up for 13.5 just needs 4 tires and a few minor little things. Great truck just no time to do what I want with it. It cranks and drives fine. Anyway here's the link hope it helps bud
http://www.brakeandfrontend.com/operation-diagnosis-and-repair-of-hydro-boost-power-assist-systems/

 

[xjmarc]

Thanks for the link. Got some reading to do. Unfortunately I'm working out of town for a few days so can't really check much on it but here's something interesting. Wife says there is a line of dead grass from the truck to where I parked the trailer. Starting to think it may be leaking fluid after all. That or it's leaking something else that kills grass.

 

[SHELBS44]

Ain't a whole lot that's kills grass besides trans fluid power steering and brake fluid At least that quick. Don't worry bout that link then get someone when you get home to pump it up while u check under it. Worst case put pressure on it with either a mighty vac orrrr redneck way air line and tape. Pressurize the system and check for leaks