electrichorseman

I have a 2012 Express Van, 1500, with the Hydraboost breaking system. When I step on the brake pedal the power steering pump strains. Also the brakes are soft. Are these signs that the Hydraboost is shot? Is there another trouble shooting procedure to do or are these two symptoms enough. Don't want to start randomly changing parts...

Beau Oszman

Fluid condition?

electrichorseman

I'll check.

0neHundredHammers

I can't help you with the diag but if your hydroboost fails, it's actually quite easy to fix. Mine failed on my 99 Express 3500. I watched this youtube video a couple of times and fixed it myself. The only issue I had was that the bolts didn't quite line up and i had to bore (enlarge really) one of the holes. I haven't had a problem since. The only odd side effect is that the power steering box whines like it's low on fluid, but its not. As long as it works, i don't mind the noise. Here's a link to the how to vid: (it's a different vehicle but the procedure is the same) https://www.google.com/url?sa=t&sour...6cYpoW2bO4MddB

electrichorseman

OK,

I replaced the master cylinder, hydroboost and the right rear caliper. The caliper had dragging issues so I opted to replace.

I bled the system using the conventional bleeding method. Fill reservoir, foot on pedal, open and close bleeder. Brakes are mushy. I've heard that because I replaced the master cylinder I have to "power bleed" due to the ABS valve being air bound? Anyone have thoughts on this? Also, could a problem with the ABS cause the rear caliper to drag?

Beau Oszman

Power bleed? Is that referring to the use of a vacuum bleed tool? Only other procedure I can think of is using an OBD scanner to cycle the ABS solenoid (fancy tool requirement warning). Much easier to bleed the master. Hope you did a bench bleed before install, there's a lot of air to evacuate.

tech2

if you have a deep or spongy pedal and you have manually bled the system with no change...try an abs bleed with the scan tool.

electrichorseman

Yes, I did a bench bleed. Wasn't easy making up the fittings for the master cylinder. (Very strange size flare fittings.) Although I was careful capping off the brake lines during the replacement I'm sure some air got in there during the installation process. I may opt to bring it to a service garage for the bleed. You're the second person who told me about the ABS module cycling tool. Sounds like a big expense for a one time use.

electrichorseman

Yes, I did a bench bleed. Wasn't easy making up the fittings for the master cylinder. (Very strange size flare fittings.) Although I was careful capping off the brake lines during the replacement I'm sure some air got in there during the installation process. I may opt to bring it to a service garage for the bleed. You're the second person who told me about the ABS module cycling tool. Sounds like a big expense for a one time use.

Beau Oszman

You'll still have to bleed the master at the fittings also after install. Never once bled an ABS module, even after replacing a master. Could be, just wouldn't suspect it.