Anyone rebuild their hydroboost unit?

[KATOOM]

I've come to the conclusion after combing through the internet looking for answers as to why my PS pump pukes fluid while the engine is off, that there must be something wrong with the accumulator and/or the check valve.  Its amazing how many people post problems with these systems but dont bother to let anyone know if they problem was ever solved...

 

So that said, I have two options.  I can buy a rebuild kit for $50, a reman unit for $200 (kinda wondering how reliable it would be), or a brand new unit for $300.  Being that I have the tools to rebuild something, it certainly doesnt mean I care to and that it doesnt mean it'll work as it should after the rebuild, I'm curious to see if anyone has tried it.

[IBMobile]

Here is an article on the subject. 

 

[KATOOM]

Thanks IBMobile, I've seen that.  My only reason for asking was that article only involved swapping out the middle seal and nothing else.  If I'm going to get a rebuild kit then I'm going to fully rebuild it with all parts since I'm not sure whats the matter with it...  Thats kinda why I'm wondering if I should just save myself the energy and get another one.

[Royal Squire]

If I remember correctly I believe @Haggar rebuilt a brake booster. Had a description and some photos. No idea how to find them. 

[01cummins4ever]

I haven't seen any complete articles on hydroboost rebuilds but between this thread and the one IBmobile posted it should cover the bases, @Haggar gave some insight on how to split the brake rod from the hydroboost so you can replace that seal too. All in all a fairly straight forward job, not as complicated as it sounds, I rebuilt mine about a year ago, but not related to my power steering pump overflowing, I did not replace the seal on the brake rod, but so far so good, no leaks

[IBMobile]

There is also another link to rebuild the booster but every time I click on it Cox says they can't find the link.  Here it is below.

 

http://articles.mopar1973man.com/general-cummins/33-brake-system/79-brake-hydrobooster-rebuild

[dripley]

I just did mine and for the most it is quite simple. And you dont need 75% of what comes in the Pirate kit. Resealing the shaft from the brake pedal is the hard part. Due to thunderstorms and having to leave the next day I did not mess with the shaft. Maybe another day for that but so far the shaft is not leaking even though I did not do a thing to it. The only internal seals I replaced were between the 2 case halves and the seal in the bore for the power piston. There was also a seal between the master cylinder and booster that I replaced. Best I could it was leaking from both of the those seals. For now it is leak free and works fine.

 

Seems this is the one that @01cummins4ever linked also. At the bottom of page 2 Hag shows what he did to get the rod out. I just did not have time for that. I got alot catching up to do when I park this thing for a new head gasket.

 

Edited August 13, 2018 by dripley

[Haggar]

Its crazy, but the only thing that can be "hard" is if the brake pedal rod is staked to the input of the hydroboost.  Otherwise it is super straight forward.  

 

Keep in mind, the one I rebuilt was from a GM truck (same hydroboost unit)  The input rod was staked  (not all years of GM were staked, many had an adjustable rod).  I am not sure whether the Dodge units are staked or not.  The FSM is no help, as hydroboost repair was not a dealership level operation.  You replace it as a unit. 

 

If you buy a replacement, make sure, before you install it, that the brake pedal rod is the same length as the one you are replacing!!!!  this is about the only difference between the hydroboosts.  (the other is the color of the accumulator.  This designates the precharge pressure.  I have yet to see much of a difference, but I image it has to do with the number of brake pedal applies of boosted brakes with the engine off balanced against the operational pressure of the power steering pump.)

 

GL , HTH

 

Hag

[dripley]

My unit was staked and you cannot replace those seals without removing the rod. It took me longer to remove and replace the booster that it did to reseal it. I did not mess with the accumulator, it seems to still be working fine. It took about 7 strokes to bleed the pressure off.

[Haggar]

Drip,

 

Thanks for the update....  I didn't know if the Dodge units were staked or not.  That does make it a bit more of a hassle, but not the end of the world.

 

Hag