Hydroboost or Master Cylinder? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Bob Q · 11-13-2018, 01:44 AM

On my dad's '84 K2500 diesel, we noticed the brake pedal is now bleeding off when the brake pedal is depressed. Other than that, the brakes seem fine. Do you think that sounds like the hydroboost is going out or the master cylinder?

Thanks!

**mongocanfly** · 11-13-2018, 02:27 AM

the hydroboost wont cause the brakes to bleed down...the hydro just assists the pedal like a vacuum booster does... sound like the master

sweetk30 · 11-13-2018, 01:45 PM

and it will get stiffer if there is less boost from the hydroboost unit .

hydroboost units rarely go bad except for massive dirt in system or bad seal . otherwise they just work and work .

i just put one back in service that has sat for 10 years in my parts stash . still had the system closed with p/s pump/lines / box all hooked to it . but installed it and she is working .

Bob Q · 11-14-2018, 12:38 AM

Thanks guys. I'll check it out.
Posted via Mobile Device

11-13-2018, 01:44 AM	#1
Bob Q Registered User Join Date: Jun 2003 Location: California Posts: 71	Hydroboost or Master Cylinder? On my dad's '84 K2500 diesel, we noticed the brake pedal is now bleeding off when the brake pedal is depressed. Other than that, the brakes seem fine. Do you think that sounds like the hydroboost is going out or the master cylinder? Thanks! __________________ Bob Q. '83 K2500 6.2L

11-13-2018, 02:27 AM	#2
mongocanfly Post Whore Join Date: May 2015 Location: Alabama Posts: 14,692	Re: Hydroboost or Master Cylinder? the hydroboost wont cause the brakes to bleed down...the hydro just assists the pedal like a vacuum booster does... sound like the master __________________ Mongo...aka Greg RIP Dad RIP Jesse 1981 C30 LQ9 NV4500..http://67-72chevytrucks.com/vboard/s...d.php?t=753598 Mongos AD- LS3 TR6060...http://67-72chevytrucks.com/vboard/s...34#post8522334 Columbus..the 1957 IH 4x4...http://67-72chevytrucks.com/vboard/s...63#post8082563 2023 Chevy Z71..daily driver

11-13-2018, 01:45 PM	#3
sweetk30 Registered User Join Date: May 2012 Location: horseheads,ny rust belt Posts: 2,794	Re: Hydroboost or Master Cylinder? and it will get stiffer if there is less boost from the hydroboost unit . hydroboost units rarely go bad except for massive dirt in system or bad seal . otherwise they just work and work . i just put one back in service that has sat for 10 years in my parts stash . still had the system closed with p/s pump/lines / box all hooked to it . but installed it and she is working . __________________ 77-k30lb BIG truck build . 87-k30lb budget beater build . 85-k30lb the plow machine build . 85-c10sb summer fun toy . ----------------------------- HOLLEY SNIPER efi = worst case of p.i.t.a i ever had . EDELBROCK pro flo 4 = best deal going so far . love my setup works great.

11-14-2018, 12:38 AM	#4
Bob Q Registered User Join Date: Jun 2003 Location: California Posts: 71	Re: Hydroboost or Master Cylinder? Thanks guys. I'll check it out. Posted via Mobile Device



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