truth or a lie

[big d]

i was recently talking to a guy that scraps vehicles for a living and sells parts on the side. he told me that cast iron master cyclinders are for heavy duty application as part of the heavy duty chevy option, and that the plastic master cylinders are for lite duty ? wtf ? most of the pics i see of guys that have the 80's-90's blazers, almost all of ya have the plastic master cylinders. lmc list cast master cylinder application up to like 91'.i figured gm just got cheap and went plastic. any truth in the words of the lite/heavy duty types ? thanks. /forums/images/icons/grin.gif

 

[Pure Insanity]

Mines 86 and is plastic. I dont know how much reality there is to your friends idea. The plastic is just a reservoir. Theres no pressure in it. My 84 Camaro had a plastic tank too. I worked at a Chevrolet dealer up until a few months ago and all the newer trucks and cars are all plastic tanks. I dont know about cheap, as the master itself is alum now. Maybe they did it for a few lbs weight savings. OK I rambled long enough. /forums/images/icons/tongue.gif

 

[MudbogAD]

I have a cast iron.

 

[nvrenuf]

It has nothing to do with any "heavy duty" options, it's all about year models. During the the 80's GM started using the plastic resevoir m/c's on just about everything.

 

[Grim-Reaper]

Cheap and easier to manufacture. Casting the tank in plastic is very fast. Less metal used, Less machine work needed. What determins it's application is the bore size and pressure it's capable of producing, not the fluid resivior.

 

[big d]

thanks, thats what i thought.

 

[big d]

thank you for the info

 

[big d]

thank u 4 the info and reply /forums/images/icons/grin.gif

 

[6.2Blazer]

My '90 has the cast reservoir but my guess is because of the hydroboost system (it has the 6.2 diesel). The idea that this means the system is heavy duty might be correct just because the heavy duty system has the cast resevoir.......but the cast reservoir is not why it's heavy duty.

 

[Dieselmh]

Great, now Big d is gonna thank you too!

 

[k20]

i got the iron one, its a 350TBI, i would get a light duty K20 since its got the 14SF and had 2 leaf front springs originally. Course since mines 87 they mighta just been cleanin out the old inventory, i dont know

 

[Blazer_Boy]

Plastic is easier to check, only takes a quick glance. I feel its better deal than trying to get that damn hold down bar off the metal ones.

 

[big d]

boy do ya got that right. bust your knuckels take'in em' off and about the same puttin' em' back on ! thanks for the reply. /forums/images/icons/grin.gif