Hydroboost disscusion

[Black_cirrus]

I need to replace the hydroboost in my 95 K2500 Burb as its leaking where it bolts together. I can not figure out what the metal piece bridging to the low pressure return is, not sure what this part does as it seems to be only on this model of booster.

You must be registered for see images attach

I have a unknown junkyard booster I got from a coworker with a bad accumulator and a 2004 2500 Burb at work I can look at for reference. I have a thought on a way to bolt a NBS MC to a bolt on GMT400 hydrobooster without machining the booster or MC

 

[grampadirt]

Mine had it as well.Not sure what it does but the rebuilt unit I bought didn't have one,but I installed it anyway.It's been on the Burb for about two years now and the brakes work fine.BTW I replaced all the fluid in the system at that time.

 

[Black_cirrus]

I have a theory what its for could you post a pic of your current unit please?

 

[grampadirt]

Of course...

You must be registered for see images attach

 

[grampadirt]

You must be registered for see images attach

 

[Black_cirrus]

Thanks, I think they updated the casting and moved the bypass that tube did to an internal function on the hydroboost. I seems the older castings don't have the second plug above the master cylinder. Now all I need is the time and money to figure out the rest.

 

[Black_cirrus]

Well I was wrong, My hope was if I took the Hydroboost from a C3500hd (Rock Auto had an AcDelco for $85 +20 core) that has over a 1.5inch Master Cylinder it would have a bigger bore to hold the NBS Master Cylinder. It bolts in but the pushrod stuck out to far lucky for me the push rod from the junk yard unit fit perfect. So I have a Reman booster with what should be the high pressure accumulator I think, and to the door was only $110.