Got My Rear Discs On

[gator2511]

Ive been wanting to do this for a while and finally just got it done. Bought a kit from Blackbirds and found it to work really well. Randy was a great help and doesn't forget you when your check cashes.

















I'm using the stock prop valve and master cylinder. I had to adjust the parking brake and play with the cables a little to make it work. I also had to make a bracket for the parking brake to replace the backing plate that held it stable. I am very pleased with how the whole system works without any other changes. I'm going to drive it for a while and try to find a nice wet slick skid pad to test out how stable it stops in the wet.

[clos69]

That is awsome..If you don't mine me asking how much was the kit..what was all included and do you think I can put this on a 4x4 Blazer?

[gator2511]

Thanks! The kit was $585. It includes the calipers, rotors, brackets, mounting hardware and new short flexible brake line. Check with Randy about your application, he really is very helpful. blackbirdscustomtrucks.com

[hchad18]

I love the way rear disks look.

[tim21391]

is that $585 shipped ?

[gator2511]

Originally Posted by tim21391

is that $585 shipped ?

Free Shipping!

[gator2511]

Originally Posted by tim21391

is that $585 shipped ?

Free Shipping! You can buy the kit without the parking brake and the new short flex line and its less money. I got the one with the parking brake although I really don't need it here.

[jholley]

Nice Work, Looks Great!

[71meangreenc10]

Just curious,
You said you were using the stock prop and master cylinder, your not using the one that was with the old drum brakes are you?

Smitty

[gator2511]

Originally Posted by 71meangreenc10

Just curious,
You said you were using the stock prop and master cylinder, your not using the one that was with the old drum brakes are you?

Smitty

Yes I am using the MC and Prop valve that I used with disc front and drum rear.

[gator2511]

71meangreenc10, Are you thinking I should have changed the MC and prop. valve? I have read that you should do this if the rear brakes are heating up. My truck stops great and the brakes run cool. The rear discs are not any hotter than the front. I've had it in traffic and on the interstate for a 30 mile run at around 75-80 mph, pulled over and felt the brakes and they were great. The old disc/drum prop valve and mc setup seems to be working great but I'm not against more changes if they are needed to be safe. Any input from you and other folks will be appreciated. Thanks, Gator

[chris71]

i am actually suprised that you arent having any braking issues with the rear, and yes you should have switched over to a disc/disc MC and prop valve. if it were my truck i probably wouldnt be driving it. disc brakes require less psi and more volume to operate due to their design differences over drum. so right now, you are sending way too much psi and not enough volume to the rear. the volume may not be an issue now, but when your rear pads get thin you may be running out of fluid in the resivoir to push the pads to the rotor, which would mean substantially less braking power to the rear. I would absolutely call randy and ask his opinion since it is his product. spend the extra money and do it right. after all, crappy brakes=wrecked truck or hurt people

[gator2511]

Well I did ask Randy what he thought and he said most times your stock set up will work fine. He said to try it out and if it was a problem to call him. I thought I would ask the board for advice. It works great now but if it needs to change then I'll do it. Its kinda like if it aint broke don't fix it. I would not drive the truck if it didn't feel safe but it stops better than it ever has .

[71meangreenc10]

Im suprised more people havent jumped on this but,,,,Chris is right that the systems use different pressures, props are designed differently for disk/disk, disk/drum applications.I have talked to MP Brakes, CPP and googled alot. I would really get alot of opinions before I would leave that setup on my truck. Just peace of mind. Now there are different bores on the master cylinders that will affect your braking, I had a large bore and now I am getting a smaller one for my truck. Large bore did not do the job. I am also putting glocks kit on my short bed, the cadillac calipers in my opinion are garbage and I hate them. The camaro calipers look alot better. (my opinion).

Smitty

[gator2511]

I FEEL THE LOVE MAN!!!! o.k. My calipers suck and the truck is dangerous to drive. Now what master cylinder and prop valve are you guys using to make this combo safe? I'd like to have some real world experience from you guys before I buy more stuff.

[chris71]

Originally Posted by gator2511

I FEEL THE LOVE MAN!!!! o.k. My calipers suck and the truck is dangerous to drive.

your truck may not be that "dangerous", as you said it stops better than ever before, and i am sure there are guys out there right now with the same setup driving for years with no "apparent issues" but we are just trying to help you get your truck "spot on" and help to try and minimize any potential issues that may arise

[gator2511]

I am always looking for information to make my truck better. I appreciate your input. Your point about later on is well taken. I'll most likely change the mc and the prop. I'm just hoping to get some of the guys to tell me what they are using so I can have more info. Thanks

[chris71]

Originally Posted by gator2511

I am always looking for information to make my truck better. I appreciate your input. Your point about later on is well taken. I'll most likely change the mc and the prop. I'm just hoping to get some of the guys to tell me what they are using so I can have more info. Thanks

Yeah hopefully some guys with rear disc will chime in, but i think that as long as you get a mc and prop for disc/disc, for our years of truck you would be fine. mc's are designed to work with the vehichle they are for, i.e. the bore size controls the amount of psi and volume being sent to the calipers. theoretically, on a light car like a vette you wouldnt need as much psi as you would on a heaveir vehicle like our trucks to make it stop in the same distance. any of the big vendors like master power, CPP, etc should sell these mc's for our trucks. maybe a site vendor will chime in as well

[mr48chev]

The deal with the residual valve is that in some cases it may cause the pads to drag more than desired on the rotors.
.
I've checked with a couple of different vendors and they gave the same response that Gater 2511 got.

[chris71]

Originally Posted by mr48chev

The deal with the residual valve is that in some cases it may cause the pads to drag more than desired on the rotors..

I believe mr48chev is refering to the residual valve that is built into the mc for a disc/drum MC, see drum brakes have that residual valave to keep a few psi in the brake fluid to put some pressure on the cups of the seals in the wheel cylinder to help avoid leaks. this few psi is still there on your rear discs, which i would imagine is causing the pads to start to drag on the rotors even with your foot off the brake, such as mr48chev is suggesting. you see there is quite a bit of engineering that is involved in brakes. it is important to understand some of this brake theory before changing things around. thats why so many guys end up having problems. please see one of my earlier posts on volume, things may be peachy now, but when your rear pads get thin you may not have much rear brakes at all (depending on the volume requirements of the rear calipers). i dont like to take chances and go on feel alone, from a brake theory and engineering standpoint your setup is wrong. hope im not sounding like a nagging mother here, just trying to emphasize the importance of properly working brakes.

[71meangreenc10]

Currently I have a MP brakes master cylinder with a CPP prop valve, and the dreaded Cadillac calipers. I do have a CPP master cylinder in my garage that will go on with the glocks camaro stuff. My MP brakes master cylinder has a bigger bore than the CPP one. So I cant compare anything at the moment until it gets changed. I do aggree that when you go from drums to disks in the rear its 200% different. I like it and how it rides(but currently having issues) and want to do it for my burb, but I have to get a warm and fuzzy on the conversion before I put my kids in it. If not,,,,I will go back to drums on the back.

Smitty

[gator2511]

So You think one should stick with the origional bore size? It does seem that bigger bore would equal more fluid movement and more caliper movement. You are not happy with that though? How does it feel? I have to laugh when you say the Caddy calipers are bad cause I'm already committed. What kind of issues are you having ?

[71meangreenc10]

Well,
I dont even know where to start with the bore size issue. I am really disgusted with the whole rear disk conversion for my truck and way too deep in with cash on it....I told CPP what i was doing and they sold me the kit,,,without Prop or Master cylinder. Then I researched found out I should change the MC and Prop...Called MP cause they were just down the road from me. Got there MC, got the Prop from CPP..

When I first put it on the brakes were amazing, Stopped on a dime and you would hit the window if not careful. Then it just got weak. No leaks, blead them with all kinds of stuff,,,manual bleeding, pressure bleeding, no luck,,,brakes were crap. I hate the park brake in the caddy calipers too.

Then I called CPP again and told them what was going on and they sent me there MC which I havent put on yet due to deployment,,,yada yada yada,,now I am moving across country (AGAIN) so it will have to wait.

It would have been nice when I bought the kit that CPP would have said "hey you need x y z" to make this work properly, but they didnt. In my opinion they should have. Cause everytime I called them, they were like yeah you need this. So why didnt they do this from step one,,,I dont know.

Back to bore sizes,,,there are a few and I can tell you that I have a large bore, and its not giving me a good braking when applied, like it did the first time I put it all together. But it also could be the calipers too. Mine dont even have 500 miles on them and they are garbage.......

HATE HATE HATE the caddy calipers....

If you ever say Office Space....The caddy calipers will get the same fate as the copier/fax.....

Smitty

[gator2511]

I'm sorry to hear that. I have been there before myself on other stuff. Once you get started you have to keep going or lose the whole thing. I have to say that so far the Caddy calipers have worked very well for me. I like the parking brake.I don't know what the diff is. You guys made me think about all this and tonight I ordered a new disc/disc master cylinder and prop valve from CPP. Really though I thought all along I might have to replace them but hoped not.Although the brakes work great right now I just want to be sure they stay that way. Thanks for the help and good luck to you.

[chris71]

gator, let us know the results when you get the new mc/prop on, good luck to you