1990 Suburban Master Cylinder Upgrade

[dag4566]

Have an LS swapped V1500 1990 suburban and just trying to do some upgrades as I work on it.

I have new pads, rotors, and drums/shoes and the pedal is a little squishy then gets hard. I bled out some nasty fluid and it improved slightly but I am wondering if there is a possible GM part upgrade. I have researched and found a 99-2000 master may be the ticket, just need some guidance. I have these options, just need to know what I should order to upgrade. Any help would be appreciated.

Thanks,

Z82	Heavy-duty trailering package

Z83	Heavy-duty chassis package

Z85	Heavy-duty suspension

 

[Ricko1966]

Newer master cylinders are designed for low drag calipers,the bore designs are changed.

 

[dag4566]

Mine has the 90-91 plastic resivior and ABS if that makes a difference

 

[nvrenuf]

@dag4566 i have a 91 Blazer and I’m using a 99 C3500 m/c (for 4 wheel disc) on my original vacuum booster.

 

[Ricko1966]

I wouldn't change anything until I figured out why my OE stuff wasn't working right. Your pedal shouldn't be squishy and then get hard. Have you adjusted or checked adjustment on your rear brakes that's a biggie a lot of people don't think about.

 

[Keith Seymore]

Have an LS swapped V1500 1990 suburban and just trying to do some upgrades as I work on it.

I have new pads, rotors, and drums/shoes and the pedal is a little squishy then gets hard. I bled out some nasty fluid and it improved slightly but I am wondering if there is a possible GM part upgrade. I have researched and found a 99-2000 master may be the ticket, just need some guidance. I have these options, just need to know what I should order to upgrade. Any help would be appreciated.

Thanks,

Z82	Heavy-duty trailering package

Z83	Heavy-duty chassis package

Z85	Heavy-duty suspension

Z82/83/85 have nothing to do with brakes.

K

 

[dag4566]

I read that trailer packages changed drum size.

 

[Keith Seymore]

No.

The brake size is specific to the brake RPO (JB5, JB6, JB7, JB8).

K

You must be registered for see images attach

 

[nvrenuf]

@Keith Seymore do certain rpo’s like the trailer pkg trigger the inclusion of others like the bigger brake rpo’s?

 

[Keith Seymore]

No.

You can see from the chart above that the only thing that drives the specific parts is the brake system RPO.

K

 

[Jrgunn5150]

My C10 is a GMT800 Tahoe master with an S10 reservoir.

Has rear discs on a Ford 9.75 axle.

 

[Scruffy49]

I just want to swap the plastic reservoir over aluminum stock 85 mc for an all metal mc… 1.25” rotors with 11+” rear drums… Worked just fine, looks like a shaved down dirty dog’s butt… Truck is going full lowrider with 60s/70s style underhood trimming, yes that means chromed alt-ps-pb components, braided stainless hoses/lines, ribbed cast aluminum valve covers/aircleaner… Plastic has to go away.

 

[cyclic]

Take a good look at my old thread 88 Burb complete brake upgrade

Most of the pics are gone, but the info is good and very on point for 1/2 ton square bodies.