Dual brake reservoir, rear section is for rear brakes?

[K1500_Dude]

1995 K1500 4x4 5.7L

The rear section of the brake fluid dual reservoir was very low. Front section fine.

Truck brakes fine. No sign of leaks so far.

Is the rear section of the reservoir for the rear brakes?

[Chevy_Finatic79]

you got it the rear section is for the rear brakes at least mine is that way.
The brake system is a (closed system) leaving fluid nowhere to go except from the resivor to the calipers/wheel cylinders if it was low your wheel cylinders "could" be leaking sometimes it is hard to tell unless you take off the rear wheels and the drums, but sometimes you can plainly see a wet tire or "backplate" that holds the brake shoe assembly.
brake fluid doesnt just evaporate I would take a closer look at your whole brake system.

for me brakes are the most important system and one that absolutely has to function properly before I'll drive cause I've had brakes fail on me at fast speeds and it aint fun.....

[crabtruck]

Welcome to the forum k'dude
That's the opposite of my 94 which uses the much larger rear section to handle the bigger front pistons.
Don't know what it's like for 4w disc. It uses the front of the combo for the front though.
So if your system is like mine, you may need to replace worn front pads.

[mudseeker]

if the rear section of your reservoir is low, i would look at the piston o-rings. if they have failed then the fluid could be leaking into your brake booster. also check for a crack in the reservoir and work your way down the line to the wheels.

[K1500_Dude]

Originally Posted by crabtruck

Welcome to the forum k'dude
That's the opposite of my 94 which uses the much larger rear section to handle the bigger front pistons.
Don't know what it's like for 4w disc. It uses the front of the combo for the front though.
So if your system is like mine, you may need to replace worn front pads.

Yes, this 1995 has the rear reservoir MUCH larger than the front. And it has front discs and rear drums.

Looks like some more detailed looking will need to be done.

[K1500_Dude]

Originally Posted by mudseeker

if the rear section of your reservoir is low, i would look at the piston o-rings. if they have failed then the fluid could be leaking into your brake booster. also check for a crack in the reservoir and work your way down the line to the wheels.

I did read that THAT could be a possibility too. Hmmmm.... does the fluid just collect into the booster? Will it leak down somewhere along the firewall? Or into the under-dash area inside the cab?

I figure there's no way the fluid gets sucked up into the booster and then sucked into the engine to be burned?

[mudseeker]

it is possible that the engine will burn the brake fluid. the engine vacuum moves the diaphragm inside the booster to assist braking and could pull the brake fluid into the engine.

i changed a leaky MC on a buick about a month ago. it was leaking past the piston and would drain the reservoir in less than a hour. it was so bad, you could see it drain as you filled it. lol

[crabtruck]

asking for more work too early, check front pads, they will hold a lot of fluid.

[K1500_Dude]

Originally Posted by crabtruck

asking for more work too early, check front pads, they will hold a lot of fluid.

Yep, planned on looking at the pads first.

They only have a few K miles on them tho. So..... either the calipers are hung up (but no noticeable drag while driving) or there is a leak. Remote possibility that the fluid was not replenished when the brakes were bled.

Thanks everyone for your replies.

[o3shortbed]

i have an o3 silverado and it was leaking where the booster bolted to the main cylinder. a rebuild kit was 42.00 but a SBC dist. o-ring is the same size and cost like 2.00 for 2 of them at the zone. a farm parts house may have them cheaper but i like my autozone here in town. my old bus driver works there.