Originally I had a power steering fluid leak, found a line I thought was leaking, replaced, still leaked, replaced other line just to makes sure, ended up finally seeing Hydroboost leaking (didn't have a brake problem) Replaced Hydroboost, then intermittently pedal would almost go to floor, so got another Reman Hydroboost, now it's locked my brakes up, unless I'm doing something wrong it's going to be #3 reman going on this am.

Sometimes the output rod length to the master cylinder is off. Some are adjustable, some you may need to grind shorter. What happens is they can hold the master cylinder down slightly.

Sound like something wrong in the hydroboost to go both ways. Like the spool value is stuck why the brakes are lock.

 

I'll keep my hydrobooster and just rebuild it. Already done one. Not bad but be aware of the input rod seal you might need to cut and weld the rod.

Blue,

 

Keep the one you have now (if it is not too late) and check the rod that pushes the master cylinder.  Like Nissacs said it sounds too long. 

 

It will take you a few minutes to measure, you gotta reach in to depths and relate that dimension to the actual mounting surface....  but once you work it out you should be able to tell if it is actuating the brakes.

 

GL  HTH

Hag

On 11/23/2020 at 6:10 AM, Mopar1973Man said:

Sound like something wrong in the hydroboost to go both ways. Like the spool value is stuck why the brakes are lock.

 

I'll keep my hydrobooster and just rebuild it. Already done one. Not bad but be aware of the input rod seal you might need to cut and weld the rod.

Unfortunately, I didn't have time to order a kit and rebuild mine, was on the road in Florida when I noticed it leaking, didn't think of rod length when installing the reman in a hotel parking lot. I did figure out the rod was to long, but I think the alternate rod that came with the 2nd reman is to short. I do have two hydroboost's at home and am going to order a kit and rebuild on. But I took the rod out of my original, original, the one I replaced years ago and the rod is longer than both rods that came with the second reman. 

On 11/23/2020 at 3:33 AM, NIsaacs said:

Sometimes the output rod length to the master cylinder is off. Some are adjustable, some you may need to grind shorter. What happens is they can hold the master cylinder down slightly.

The 1st reman the pedal would almost bottom out sometimes, I never trust the quality of remans, the 2nd (I got once home) one seemed fine at first, but then I could gradually feel the brakes staying applied until finally they were smoking, by the time I got back to my shop the were all but completely locked up. Next morning was get a 3rd reman coming, I figured I try driving the truck, drove around for 3-4 miles no problem, was ready to get back on the road, went to leave and brakes locked again. Had commitments, put shorter rod in, still doesn't feel right, pedal goes to far down sometimes.  

I get it on the road repairs are a pain and yeah I get that the idea of rebuilding a hydro booster in a hotel parking lots isn't happening either. 423k miles later it might be on my list of things to do in the near future too. I've been keeping my fluids changed and flushed out often so maybe I can get it to hold up a bit longer. 

My only experience with  these hydroboost units is that off the shelf they are all the same no matter what vehicle they are on, Ford, Chevy, Toyota or anything else that uses them, the only thing different is the brake rod length which should be unique to your vehicle, if You didn’t save your original it maybe a crap shoot trying to find one that fits. I did rebuild mine s few years ago but did it with my original so their was no second guessing of the correct rod length. @Blueox01 you might have better luck if you can find one in a wrecking yard out of another 2nd gen close to yours 

Agreed they are basically the same. 

 

Differences fall in 2 places (not including accumulator pressure, which is designated by anodized color)  input rod and output rod lengths.    I have noticed a difference of the boots that go near the firewall as a difference between my GM version and my dodge version  (could be a year thing, not necessarily a end user spec), but that would have not prevented the use, just sealing around the hole in the firewall.

 

Hag

Now today brake pedal seems fine, all day.

So still dealing with Hydro-boost problem, went and replaced pads, Pass side missing one caliper bolt, other broke????? Not back on the rubber yet to see if that was some of the problem. Skeptical, because 1ST problem was power steering fluid loss,and eventually found the Hydro-boost leaking. Anyway bought the Pirate Jack rebuild kit, wants me to cut the brake pedal shaft to install seals on regulator? shaft, maybe I bypass those, anyway couldn't get the tiny valve body out, used air to push it out, lost the check valve ball (not really a good day) have another core, be more careful on it.  

Yeah I had the check valve fall out on me while doing a customers rig. I at least seen it fall was able to see where it went. His the came apart super easy.

37 minutes ago, Mopar1973Man said:

Yeah I had the check valve fall out on me while doing a customers rig. I at least seen it fall was able to see where it went. His the came apart super easy.

This unit had set in my garage for 10 plus year, was kinda gummed in, tried loosing up with carb cleaner. good thing I have another core.

blue,

 

You don't have to cut the rod.  You can disassemble it where the shaft is peened around the ball.  you just have to make some tools to hold the shaft.

If it is not leaking at the input rod, just let that slide.  The last one I did, was leaking at the output, so I didn't spend the time on the input rod seal.  It may bite me later, but working fine right now.

 

GL

Hag

9 hours ago, Blueox01 said:

This unit had set in my garage for 10 plus year, was kinda gummed in, tried loosing up with carb cleaner. good thing I have another core.

 

Ahhh... yeah that would do it. 

4 hours ago, Haggar said:

blue,

 

You don't have to cut the rod.  You can disassemble it where the shaft is peened around the ball.  you just have to make some tools to hold the shaft.

If it is not leaking at the input rod, just let that slide.  The last one I did, was leaking at the output, so I didn't spend the time on the input rod seal.  It may bite me later, but working fine right now.

 

GL

Hag

Seems like the main problem on these is the seal for the piston, and maybe the valve sticking. I hope.

i did mine 3 or so years ago. Case leaked and I had a leak hitting the floor mat. I did not put the seal on the shaft and all is working fine. i do every so often see a drip on the floormat

I had mine even spit out a shot of power steering fluid once on my floor mat too but never seen it again after changing power steering fluid.