S10 M/C Bleeding Tips?

[David Pozzi]

The Malibu might be okay with the C5 and a 13/16....
Mr. Pozzi, that Baer track kit on your wife's '73, that has the 38mm C4 calipers does it not? ...or is the Baer kit the larger C5's? I had been assuming it was the smaller piston ones.

Those Mopar masters are not QTU, if anyone was wondering, despite their appearence.

I'll see if I can come up with a suitable 3/4" master....

You are correct, they are small and require a smaller bore master cyl.



AND you are correct the Monza style MC has less travel.
Thanks for the good info on Master cyls.

[MarkM66]

Mark, with your C4 front set up, what are you running for brakes in the rear? Before the hydroboost, were you running manual? If so, what master cylinder were you using? Thanks.

[Mean 69]

I run the matching single pot PBR floating calipers in the back, with a 12" x .810" rotor. I did run it manual prior to the boost unit, but never found a setup that I liked for the street. I had issues with the Ford M/C that I bought, I think someone mixed up a couple key parts during the rebuild, because the piston seal is beyond the fluid inlet, it would never get fluid into the darned bore. Very frustrating. I have one of the Monza 3/4" units coming tomorrow, I will give that a try.

It is getting pretty close to brake overhaul time, I am getting a bit tired of this.

More to follow,
Mark

[Salt Racer]

Mark,
Can't you go down to a part store and have them replace the Ford M/C? (assuminng you bought it locally) Wouldn't hurt to try another one since you've already made lines and all necessary modifications.

3/4" bore M/C might feel too touchy as well.

[Mean 69]

I could have, except that the bolt pattern to mount to the firewall was "slightly" different, meaning I had to break out the drill and carbide burr to elongate. They'd probably never notice, but.... To be honest, after the couple of hours making nice new lines to cut it in, then finding the bolt issue, then learning that the stupid thing would never have worked for other reasons, well, it is a miracle that the M/C did not find itself in orbit, having served as a mild stress reliever.

In the meantime, I tried a 1" unit all over again, with the Carbotech pads. No luck, the pedal effort required to really get after things was pretty high. I might try it again tomorrow, thinking that bedding down the pads might help a bit, but it is pretty clear that the large-ish bore units aren't the ticket (as we all thought anyway). Anyway, no way this would work on the street in a panic situation, might be okay on the track if track pads were to temp, etc.

This is really not fun, very clear that Paul's business is solving an issue that is otherwise a PITA.

Mark

[gen3bu]

do you guys have a pert number/application for the 13/16 unit that matches the c5 brakes for a manual setup.

btw - not trying to hi jack your post, just seems like the right place to ask this.

kevin

[68protouring454]

why not adapt the c4 mastercylinder? bet that would work
i have c5 13 inch for my 68 and i bought a hydroboost that paul set-up to use the c5 master, should be no question mybrakes ahould work, as it will be using the same c5 master, goodluck
sucks don't it mark!!
jake

[MarkM66]

Mark, I inted to run the same brake set up as you're currently running.

C4 front, 93-97 Camaro rear.

I want to run in manual mode just not sure what m/c to try.

These guys recommend a 1" m/c from a '67-76 vette. So I was going to try that.

http://touring-classics.com/accessories.htm

[Mean 69]

Don't waste your money on the 1" unit, I tried it yesterday, no luck. This is the mid-year vette unit for four wheel discs. I am running some stickier pads in the car too, but it just did not give adequate street manners. I am going to try a Monza unit today, part should be here in a shoprt while, and I will let folks know how that works out. This is really becoming a pain.

Mark

[fuzzyonion]

Pretty sure the larger C4 and C5 units ran a higher pedal ratio. A combination that works on one car doesn't mean it will work on another, esp going to manual brakes.

The older C4s ran a 7/8". That might be okay with some good pads.

[SHANE 73Z]

Hey guys,

I will be swapping to C4 front & rear calipers this year and this is what I will be using:
http://cncbrakes.com/cncbrakes.com-a...240&subseries=

This is a dual master w/bias bar setup that adapts to the stock pedal. They are available in the following bore sizes:

5/8", 3/4", 7/8" ,1" & 1 1/16"

For the C4 calipers I was recpommended to use dual 3/4" masters. This recommendation came from John @ Johns Mustangs who is a CNC dealer. This was also confirmed by Davids comments on his wifes second gen.

Shane

[fuzzyonion]

That looks cool. Doesn't look real hard to make either. It uses 2 clutch masters.
3/4" is a good choice. It will work even better on a 1stgen than a 2nd because of the different pedal ratio.

Masters working in parallel instead of piggyback also gives a firmer pedal feel.

[68protouring454]

paul at hydroboost told me the c5 master cylinder will work unreal on my 68 with the c5 master, i think he said he tweaked my internals on my boost, but i am not sure, pedal ratio?? thats just how high up the mc rod attaches to the brake pedal right??? why not change it?? i maybe wrong, let me know
jake

[andrewb70]

Mark,

I am not sure if this helps at all, but I am using the S10 MC with good results. I have the front brakes plumbed to the rear port and the rear brakes to the front port. My front calipers are Wilwood Billet Superlite 6 piston and in the rear I have single piston PBRs. The system is manual. I started with a totally dry system and it took a while to get a firm pedal. I went around the whole car about 6 times before there were no bubbles from the calipers.

Andrew

[fuzzyonion]

The Wilwood 6 piston calipers have more piston area making them a decent size for the s10 master with manual brakes at the 1stgen pedal ratio. Their combined piston area comes somewhat close to what the single piston s10 caliper has. The s10 ran the same pedal ratios as the 1stgen Camaro.

Jake, I was talking about manual brakes only. You can run a large master with power brakes if you have enough boost with no problem. It becomes more difficult with manual brakes. Some cars, like the majority of GM products, have to run a smaller master with manual brakes than with power.
The pedal ratio for manual on a 1stgen cannot be made higher without a different pedal assembly. Its already 6.2:1 anyway. To make it higher, you would need a longer pedal arm, which probably wouldn't fit well between the dash and the floor. I dont know, as I have never tried it.
It could easily be made higher for power brakes, as long as the pushrod has the correct angle.
C5 master and C5 brakes has only slightly less master:slave advantage than the C3 power brakes did. C3 used a dual diaphragm booster, but with manual brakes they used a smaller master. The pedal ratios were the same as a 1stgen Camaro, S10, and a few others. GM used 5.3:1 on most other cars and trucks.

It's all about mechanical advantage. Smaller slaves need smaller masters, or more leverage, or more boost. That's just the way it works. Stickier pads and larger rotors have an effect too, as does a strong leg.

You cant just take parts from one car and expect them to always work no problem on another. When they do, great. But when they dont, you should have an idea why before you start, not just guess. Cars have different pedal ratios, different power boosters, different weights, different needs, etc.

[68protouring454]

so i am still covered with my set-up right?? hydroboost with the c5 master??? as you said i have boost so i can overcome the other issues going on,where as with a manual sytems it needs to be perfect in all aspects??
jake

[Mean 69]

I will be swapping to C4 front & rear calipers this year and this is what I will be using:

I don't know how I looked over this, I didn't see it for some reason, but this is EXACTLY what I have been looking for. Do you have any more pictures of this? The Mustang bolt pattern is a bit different than the Chevy, but it is very most likely easy to modify the part to fit.

A small update, but important one. I tried the 3/4" M/C on the car yesterday, without success. At first I thought that I had a huge amount of air in the system, because the pedal would go clear to the floor with only moderate force, the pistons in the calipers were clearly reacting, but it was just not good. I tried three different methods to bleed the system, vacuum, pressure, and gravity. No way there is air in the system. I think what is happening is that the stroke of the M/C is insufficient to move enough fluid to overcome the piston retraction of the calipers. I still may be overlooking something, but I don't think so. I can tell you though, I have had it with the C4 stuff. All of this is a PITA, and I still don't get the thicker rotor like I really want in the front.

Brake makeover time in the near future. Very near future. Can you say "Alcon?"

Mark

[MarkM66]

Mark, that's not good news. Not sure what I should use for a m/c, . You're doing this testing in manual mode now right? Not with the hydroboost hooked up?

Is the S-10 m/c you're trying the 1" bore? That m/c and the 3/4" m/c, are booth of those for a front disc rear drum application? If so, wouldn't the rear port have a residual pressure valve in it?

[MarkM66]

Mark,

I am not sure if this helps at all, but I am using the S10 MC with good results. I have the front brakes plumbed to the rear port and the rear brakes to the front port. My front calipers are Wilwood Billet Superlite 6 piston and in the rear I have single piston PBRs. The system is manual. I started with a totally dry system and it took a while to get a firm pedal. I went around the whole car about 6 times before there were no bubbles from the calipers.

Andrew

Andrew, is your S-10 M/C for an original power disc truck, or manual.

When looking for this m/c, I noticed two different types.

AC#18M310, with power, 24 & 36mm bore.

AC#18M309, without power, 31.75 & 24.0 MM cylinder bore.

I'm assuming you used the one "with power" since you plumed the rear port (the larger bore size) to the front brakes. If so, did it have the shallow pushrod hole?

[Mean 69]

By the way, Andrew, how would you characterize the pedal effort with your system? The six pot Wilwoods are pretty close to the Alcon units in terms of piston area, so this is pretty darned close to what I expect from the new setup if I ran a 1" unit. Do you get decent rear braking performance? Proportioning valve?

Mark