1993 international hydraulic brake problem

I'm not being funny when I say this, but is there any way that you could just put a vacuum pump on your truck and just put a regular vacuum booster/ master cylinder from something similar on there? That's what I would do.

I'm completely stunned that any manufacturer would put Electronics on a truck with hydraulic brakes. But I should know better by now.

I am not going to go on and on about how I hate electronics on trucks and how they shouldn't be on there because all they do is make problems. That's not going to help you.

But if there is any way that you can convert that over, I can only tell you that the older trucks that worked on Purely vacuum with a vacuum booster/ master cylinder had zero problems and worked every day dependably and reliably. Even better than air brakes when they are bled and adjusted properly.

That's the best that I can tell you. Good luck.

 

This electric motor is only intended to create hydraulic pressure when the steering pump loses pressure so that power brakes are maintained in case of engine stall. It should run KOEO or when the pedal is depressed engine off. The electric pump should not be running when the engine is running. I haven't messed with these in some time. Maybe someone else has access to get you specific answers to your electrical questions.

 

I am very reluctant to rely on engine vacumn to power the liquid brakes system.

There were times the engines Ive had that system on (Muscle cars not big trucks) were too tired to generate the necessary vacumn for one reason or another.

Don't get me started on electronics or motors of that type.

I have said all I can think to say without confirming to the world how dumb I am or even worse clueless about the problem. I have to be in person looking over the vehicle and whatever it's making it sick in order to think things through. There are some times on the internet I find it very difficult to be good about helping without being stupid without being actually there looking the vehicle over.

I hope in some small way this plants a seed somehow.

Good luck to you.

 

F33 powers circuit 90C which is battery power to the brake pedal switch for the hydraulic brake system. After the brake switch, it goes to your diodes.

 

I would double check that. Any hydraulic brake equipped truck I've ever driven the electric pump only ever engaged when the truck was off. A safety feature in case your engine stalls. Now if this truck has vacuum assisted brakes with a diesel engine then yes you need that pump to create vacuum since diesel engines have no vacuum.

 

Hello Wade, did you get it figured out? I am in the same situation, on the same step. Whats next?