CK5
Register an account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members.

89 K5 - Recon's 1 Ton Blazer

Looks awesome!! Cant wait to get mine done. I do have a question though!! is the D60 sitting further forward, or is it an optical illusion?

A few more Beers might fix that illusion though...
 
Stupid Brakes

Ok, I have the new 1 ton calipers up front and the 3/4 ton calipers out back and a new adjustable proportioning valve. The brake fluid nearly all leaked out over the course of having things ripped apart.

I have been bleeding and bleeding and bleeding and bleeding and bleeding and bleeding the brakes, but I can't come up with a firm pedal. I know how to do it, I've done it many times, including one time at The Excalibur parking lot in Las Vegas when a line blew on my 01 Expedition. Never had an issue getting them bled rather quickly.

I understand that I have 4 brand new calipers and the fact that there was a ton of air in the system, but it seems like this is taking way too much time or I am not doing something I should be.

No leaks or seepage.

So far 1 quart of brake fluid added to system.

The pads are all touching the rotors evenly and the pistons are touching the pads as they are supposed to.

The fronts shoot brake fluid like a water hose on full blast. I shot fluid past the rear tire while bleeding them.

The rears just have a very slight amount of fluid coming out. It does come out, it just isn't under much pressure at all.

I have the proportioning valve for the rears on wide open for full force.

I am trying to get this fixed by Friday evening so I can go wheeling at Hidden Falls this weekend.

Do I need one of those residual valves for the rear system?
 
Find a shop and have them put a power bleeder on it. Best $50 or so you can spend.
 
The master cylinder doesn't have the right size pistons to be able to accommodate the rear disc brakes. Search and I think muddybuddy came up with the right size master cylinder for the rear disc trucks.
 
I dont' think so, the piston still has to move a certain amount of fluid, and a drum brake system doesn't require as much fluid movement as a disc caliper. In addition the disc/drum m/c has a residual valve in the m/c under the tapered seat to retain a couple #'s pressure on the drums.
 
I've been thinking on this for the majority of the night in order to try to put the simple explanation into terms. Pressure and volume work together - Theres no way around it (Well, there is - But we wont go into that, doesnt apply to this).

You can have all the pressure you need - But in order to use that pressure for your intended (engineered) task, you also need the (engineered) volume. You no longer have that.

Think of a water hose. It has alot of pressure at full crank and will spray across a front yard right ? Well - If you keep your same hose (master cylinder), and add a bigger spray nozzle (calipers) you dont get the volume you need on demand. If you hold your spray nozzle wide open, sure - at first the pressure is the same. But, once the pressure reduces the stored volume......

This is also why your rear brakes only weep fluid, instead of shooting like your front.

The pro-valve is controlling the balance of pressure by controlling volume. Your MC doesnt supply the needed volume for the pro-valve to be effective.

It makes sense to me, and I know what Im trying to express - I dont think I've quite worded it right though. You know to ask/call if you have questions - I'll break it down as far as I know how to in order to help anyone learn.

And, here's the thread from muddybuddy, regarding his findings of MC choice. His initial quote, below.


hey all, ive got a 1ton k5 with 4wheel discs on 42s. originally i replaced my stock master cylinder with one off a k20 but that was still inadaquate. so i went to advance auto parts and started looking up master cylinders of various truck. im actually going to start working there within the week, and i know everyone so they didnt care if i ordered and then returned them haha. i wanted the p30 one, but i dont have hydro-boost. then i found it! it actually looks bigger than the p30 van master. Part Number 102754, its off a 1999 c3500 with 4wheel disc. i just installed it, (the lines are reverse) and wow what a difference, i cant even press the pedal to the floor anymore, and can lock up if i want to. just thought i would share my findings, as i know alot of people are looking for the perfect solution after goin to 1ton with discs.



Good luck ! While your wheelin (hopefully) this weekend, I'll be rolling in fiberglass and resin :woot:



Troy B
Ft Hood, TX
 
progress? sure

new sending unit installed, it's shorter than the other one, so i may randomly run out of gas which will add to the excitement

gas tank installed, gas tank skid plate installed

all the lines except the filler neck and breather hooked up, need new ones, these are rotted like a mofo

tried to start it, hear the fuel pump, but no gas in tank, so no starty

shocks installed, the 14" Bilsteins fit motherfizucking perfect on the inside hole of the ghetto fabulous upper shock mount me and my friend made, plenty of up travel and not as angled as i had thought they would be, i think they will be perfect the way they are

front shocks (formerly the rears) installed, they have no damn rebound, so that will be a much sooner mod than previously anticipated, bbcs here i come

rear bumper installed with only 4 bolts, found the rest in my milk jug/bolts bin so i'll put those in tomorrow

still need to do the rear pinion yoke, but i want it to be day light so i can make a lot of noise

need to go get a container suitable for fuel so i can put some stupid gasoline in my tank, then hopefully it will start and not run like shizzle since it hasn't run in a long time (5 or 6 weeks)

need to bleed the damn brakes, bought that mc muddybuddy found (thanks!)

then i will fill all the fluids in the transmission, transfer case, front diff and rear diff. did i forget any?

then i will drive it and try not to crash on it's first voyage as a 1 Ton Blazer!
 
uh oh
it's always something!

It's the last thing to finish before I can drive it. But they just won't hold in drive and just barely in reverse. Pedal is mush. Maybe I need to switch out the new proportioning valve with a butt load of adapters with the stock one and see what I get.
 
I hate bleeding brakes over and over and over and over and getting nowhere
Just thinking, but are the back brakes adjusted. I can`t remember if you put disks on the back or not, but if they are still drums, it might be hard to bleed them if they are to loose. Just a thought,:dunno: but good luck!
 
Just thinking, but are the back brakes adjusted. I can`t remember if you put disks on the back or not, but if they are still drums, it might be hard to bleed them if they are to loose. Just a thought,:dunno: but good luck!

They are disc brakes. I think I need to pull out the proportioning valve and put the stock distribution block in, but I feel like I am chasing my tail.
 
Top Bottom