Bleeding Brakes 1997 International 3800

[colt45]

Hello everyone,

I’m currently in the process of replacing a master cylinder for a 1997 International 3800. For the bleeding process, I know usually you want the vehicle off, but the electric motor for the hydraulic brakes was getting HOT when I was bleeding the brakes.

I want to avoid burning that motor up, so what’s the process for bleeding this bus’s brakes? I know I’m missing something.

[PorchDog]

I just replaced all the calipers and all the rubber hoses on my 1996-- and bled them with the electric backup pump. Tried to minimize the time the electric motor ran--- stay on the brakes a few seconds at a time. Wifey in the drivers seat, and me under the bus.

If anyone needs them-- I have the Dorman part numbers for all the rubber hoses to the calipers, and to the crossover pipe at the differential. I could not find an aftermarket substitute for the lines from the master cylinder to the lines on the frame. ($$$)

[Jolly Roger bus 223]

i think you need to find the manual/procedures for a HYDROMAX brake system.

[colt45]

Originally Posted by PorchDog

I just replaced all the calipers and all the rubber hoses on my 1996-- and bled them with the electric backup pump. Tried to minimize the time the electric motor ran--- stay on the brakes a few seconds at a time. Wifey in the drivers seat, and me under the bus.

If anyone needs them-- I have the Dorman part numbers for all the rubber hoses to the calipers, and to the crossover pipe at the differential. I could not find an aftermarket substitute for the lines from the master cylinder to the lines on the frame. ($$$)

So are you putting it into accessory mode to make the electric motor run AND pressing/holding the brake pedal? Or just pressing/holding the brake pedal while the vehicle is off?

[PorchDog]

Pressing the brake pedal with the switch in the off position.

[colt45]

Originally Posted by PorchDog

Pressing the brake pedal with the switch in the off position.

Gotcha, I’m just trying to make sure I’m not doing anything wrong. Was she pressing the pedal a couple times then holding? Or just once and holding?

I only ask because after awhile of pressing and holding the pedal, the motor was starting to get HOT.

[PorchDog]

Just once and holding for maybe 10 to 15 seconds at the most.

My experience was she would press the pedal, motor would run, I would crack the bleeder open-- and a large quantity of fluid would come out then taper off, I would then close the bleeder, and holler (yell?) at her to let off the brakes. This all went pretty fast.

Then I would give it maybe 30 seconds or more to cool down. I never felt of the motor, but I tried to keep the run times as short as possible, and a period in between to cool off. You can use up a LOT of fluid doing this-- so keep an eye on the level in the master cylinder while performing this. I think I went through almost two large bottles of DOT4. My goal was to basically replace all the old fluid with new.

All my brake hoses were original to the bus-- manufactured in 1995.

[mmoore6856]

use a suction type bleeder at the wheel and you dont have to pump anything

[colt45]

Originally Posted by PorchDog

Just once and holding for maybe 10 to 15 seconds at the most.

My experience was she would press the pedal, motor would run, I would crack the bleeder open-- and a large quantity of fluid would come out then taper off, I would then close the bleeder, and holler (yell?) at her to let off the brakes. This all went pretty fast.

Then I would give it maybe 30 seconds or more to cool down. I never felt of the motor, but I tried to keep the run times as short as possible, and a period in between to cool off. You can use up a LOT of fluid doing this-- so keep an eye on the level in the master cylinder while performing this. I think I went through almost two large bottles of DOT4. My goal was to basically replace all the old fluid with new.

All my brake hoses were original to the bus-- manufactured in 1995.

Did the job yesterday and it went WAY better than the first time (probably helps that we didn’t pump the brakes multiple times). Electric motor never got super hot and got them on the road. Thanks for all the help!

[PorchDog]

Glad to be of service!

[NickySix]

Originally Posted by PorchDog

I just replaced all the calipers and all the rubber hoses on my 1996-- and bled them with the electric backup pump. Tried to minimize the time the electric motor ran--- stay on the brakes a few seconds at a time. Wifey in the drivers seat, and me under the bus.

If anyone needs them-- I have the Dorman part numbers for all the rubber hoses to the calipers, and to the crossover pipe at the differential. I could not find an aftermarket substitute for the lines from the master cylinder to the lines on the frame. ($$$)

I wish there was some way to hand make these. I just spent $345 for the 2 lines that go to the master cylinder to the frame wall. Dealer items directly from Del Val International in Montgomerville, PA. I have an 02 International 4700.

[PorchDog]

If you have an International 3800 bus chassis with Hydraulic brakes, I have two brand new genuine International hoses that go from the master cylinder down to their connection with the hard lines on the bus. They have formed metal tubes for part of their length, and flexible hoses make up the rest. Male fittings on the metal tube ends, and female on the flexible hose ends. These are referred to by International as primary and secondary hoses.

1619277C91 Hose Assy Hyd Primary

1618276C91 Hose Assy Hyd Secondary

$145 for both including shipping in the continental US.