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Leaky Hydroboost

PaulZ

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Been leaking down the front of the firewall for awhile, getting worse. Dry on the inside. Time to address. What's the current plan, just a seal, rebuild kit, buy another?

TIA
 
I hesitantly took a chance on a remanufactured one, and cross my fingers it has worked for the last couple of years or so. If you can afford a new one go for that. The problem with remaned ones is that the piston seal rides in a piston sleeve that have gotten pitted with age, and can tear the seal up. A new hydro-boost has a smooth new piston sleeve to ride on. The only problem with new ones I have heard of is that Chines manufactures have a tendency to use cheap seals on them. The ultimate in hydro-boost is to buy a new one made in China, and then take it apart to re-seal it with quality seals. Then you will have a nice hydro-boost that will last a long time.
 
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Thanks guys. The auto parts store tells me they have one if my brake pedal is part number such and such..Is there two different ones for an 83 K5?
 
Thanks guys. The auto parts store tells me they have one if my brake pedal is part number such and such..Is there two different ones for an 83 K5?
Probably, there seems to be multiple applications for everything on these trucks. I second the replacement, I dealt with a leaky one for a while and finally bought a new one. No issues, easy swap, should have done it right away when I noticed a leak.
 
So it seems like the problem with mine would be "Input Rod Seals", but adding up various statements in the Piratejack instructions (https://piratejack.net/template/img/KIT50_KIT501.pdf) implies that it's a waste of time.
In order to service seals on the input rod end, the pedal rod must be detached to allow removal of the power-piston assembly from the housing cover. Hydro-boost with a staked pedal rod and input rod diameter of .680” or greater are servicable with an input rod kit and replacement pedal rod.
NOTE: Units with a staked pedal rod and input rod diameter of .600 or less ARE NOT SERVICABLE. Service in this area is by unit replacement only
  • We do not offer any pedal rods
  • We do not sell the accumulator, spring, or any other parts for your hydro-boost unit other than the seal kit & what you see pictured
Push Rod Removal - Staked Design 1. Saw pedal rod in half

Then there's no mention of replacing the rod or welding the old one back together. The implication is that pulling the ball out of the staked socket will crack it. So...what's the point of the kit on these units? Only seal up the output and the figure-8 seal? Maybe all the remans are getting a new input rod? Anybody cut and weld it? Maybe the boot can be saved by cutting near the eyelet and using a wet rag?

1722257485686.png

Obviously mine is the tapered shaft style they're talking about. If you get a reman and the pedal push rod is the wrong length, I guess you keep sending them back and trying different applications? That's part of why I was so interested in just replacing the seals.

roddifferences-jpg.241358
 
I sent mine to Power Brake Exchange in San Jose and for under 200 mine was rebuilt and and have had zero issues
1 408-292-1305
 
I used a method pretty similar to the one above with the red vise, except instead of a notched plate, I used the end of a box wrench. Seems to have come apart and gone back together with no issues.
 
late to the show but I have done this many times. When the rod on the unit removed doesn't match the replacement and trucks gotta roll in the am or 4-8 guys are standing around waiting for a truck.
 
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