Curtisyz54

iTrader: (5)

Look in my pics above. I used the adapters that came with the strange m/c. Then flared on 3/8 fittings on the lines.

Beeman

These are 20+ year old cars that we're modifying to go faster..new brake lines should be what you want not adapters.

xpndbl3

iTrader: (5)

ok Beeman the fitting on mine was 9/16" and 1/2" I think, how would you put a 3/16" brake line fitting into that size hole?

Curtisyz54

iTrader: (5)

You have to use adapters buddy. You cant put a 3/8 Fitting on a 1/4 inch line. The rear brakes have 1/4 line, and with the strange M/C the fittings that come with it (that you HAVE to use) will only except 3/8 fittings. Also, I did use new line.

Beeman

Actually you can use a factory line nut just like the factory did on those Mopar MC's and not use an adapter. Takes a few minutes in the junkyard or you need the adapters you're talking about.
I was talking about the difference between a standard brake line double flare used on older vehicles and the newer bubble style flare used on later cars.
https://www.thirdgen.org/propvalve Talks about the difference in flares.

Curtisyz54

iTrader: (5)

I tried using fittings with a bubble flare with the m/c with out the adapters. It doesnt work. I tried everything, I didnt want to use the adapters that were included, But I had to.

Beeman

The master you bought doesn't take a bubble flare, it's made for a old style double flare. Your car was built with bubble flares.

http://store.fedhillusa.com/316475mmtubingandnuts.aspx scroll down and you'll find 1/2 and 9/16 nuts for 3/16 line
http://store.fedhillusa.com/14tubingandnuts.aspx scroll down and you'll find 1/2" and 9/16 nuts for 1/4" brake line

http://www.fedhillusa.com/ Here's a picture and description of double and bubble flares

Curtisyz54

iTrader: (5)

I know the differance in bubble (metric/iso) flare and double flare.
And like I have said TWICE the master cylinder would ONLY take 3/8 double flare. You CAN NOT put a 3/8 fitting on a 1/4 line. Meening you you have to use a adapter to go from 7/16 on a 1/4 line to 3/8 using an adapter. I know the car originaly came with bubble flare but it doesnt matter cause I cut them off and flared on 3/8 fittings with a double flare. This isnt my first rodeo.

loneroad

iTrader: (3)

i put the stange small bore m/c on. Pedal is rock hard, got to stand on it to stop it. I have 4 wheel iron calipers. All bled. hole drilled, all instructions followed. I have the prop valve all the way open, and front brakes are in the first hole( firewall)on the mc.
New pads, rotors, etc. Im wondering if i got the wrong mc in the box, is there any way of checking while still bolted up?

If thats not it I guess im gonna drop bore sizes to build more pressure, anyone have a educated guess to which one i should try out of the 3? 15/16, 7/8, or 13/16?

xpndbl3

iTrader: (5)

i run the 1.06 bore with ls1 dual piston front calipers and lt1 rear calipers, you'd need a smaller bore than that with stock brakes all around for sure.

stage20

iTrader: (3)

all of those aftermarket big bore mc are going to have a hard pedal.

i run a dodge caravan mc. you can buy them new or reman for several different models that year. factory lists specific models at 7/8 or 15/16, im not sure which you get at the parts house. i never measured mine. pedal is stiff, but the harder you press it, the better it brakes. ive pressed on some pedals that were so hard that i thought i couldnt even press the pedal. manual brakes seem to be hit or miss depending on selection of parts and how each person perceives how easy it should be to press the pedal. bottom line, no manual combo will ever feel close to power assist.

loneroad

iTrader: (3)

Thanx guys, Im gonna run down to napa tomorrow and bug them for a bit.

Any thoughts on starting at the smallest one and trying that one first.

The MC from the 88 dodge daytona.

loneroad

iTrader: (3)

88 dodge Daytona turbo 4wheel disc MC is 7/8.
88 dodge Daytona turbo disc/drum is 13/16

stage20

iTrader: (3)

88 dodge carvan is 15/16 according to factory specs.

if you buy a reman, i wonder if you get the factory spec or whatever was sent in for a core to rebuild that day. may be random sizing.

loneroad

iTrader: (3)

i ordered a new small one, gonna try that one. hopefully i should be able to dial that one in with the prop valve. Should have results next weekend.

itsjustabird

iTrader: (1)

I fought pedal firmness issues forever! Thought I had the small bore mc turned out I didnt. Alot of the parts store units are the largest bore version so do your homework with the chrystler unit. Also when I first did it I thought I had my hole drilled in the best place(on the pedal), well after some changes I pulled it all out and there was room to go another inch down without bind so I did that and the pedal was ALOT better. Now I have 6x 4piston calipers and its as easy and smooth as the power set-up.

loneroad

iTrader: (3)

I mounted the m/c and bled it 3 different ways, but i'm having a problem with it not releasing the calipers. I have the push rod adjusted all the way back, but i dont think its enough. The calipers are grabbing the rotors now,I'm gonna start loosening the m/c from the fire wall. If the calipers release, then that def means the push rod is to long.

Any other ideas, opinions?

KWIK84

iTrader: (5)

Is it holding all four brakes? If so chances are it is in the M/C. Check you distances from the mounting face, to where the pushrod hits on the back of the cylinder. If it is a reman unit there may be some tolerance stack up issues creating the problem.

stage20

iTrader: (3)

are you using an adjustable pushrod?

loneroad

iTrader: (3)

Yes sir its adjustable. It was bottomed out. I put it in neutral.and started loosening the MC nuts. About 2 turns and the calipera released. I pulled the push rod out and ground a 1/4 in off. Now ro just bleed it again.

loneroad

iTrader: (3)

The 13/16 is a fail. While the pedal is buttery soft, its not enough to get the wheels tp even get close to locking.

itsjustabird

iTrader: (1)

It should still grab fine sounds like air.

xpndbl3

iTrader: (5)

did you bench bleed the master and the lines extremely well?

itsjustabird

iTrader: (1)

As said bench bleed again! And again and again. U get the point. Make sure the tubes u use are completely submerged. Work them slow to get all the small air bubbles out

loneroad

iTrader: (3)

Thats not what it feels like. Ive bled the MC 3 times. Vac bled, reverse bled, and the old standard pump and hold. No air.

The best way I can describe iy would be like squeezing a tube of caulk in acaulk gun aand the tip is clogged and the caulk rolls back around the piston .

loneroad

iTrader: (3)

The 15/16 out of the caravan is the sweet spot. Great pedal, great stopping. Im going to go back and do some light sanding on the pads and rotors, and knock any glazing that might be there.

Definite improvemnt.

A.Delaney

Ok guys, I just did this conversion tonight also. Strange 1.032 bore master cylinder. Everything seems fine except. One of the 1/2-20 adapters that came with the kit drips fluid. Its in the front port. It will drip very little with the pedal pumped up and holding it. Doesnt drip at all just sitting there. I looked everything over before assembly. I didnt see any damage to the adapter or master cylinder port. I tried tightening it some more, but I dont want to strip it. Other than just replacing the adapter. Is there anything else I should check? That line goes to the rear brakes.

Beeman

Is it leaking between the MC and the adapter or between the adapter and the brake line? Either way you'll have to pull it apart, just narrow down where you're looking for the problem. It all seals together on flares so be sure it's all spotless with nothing on the flares, seats or threads. If it's at the line check the flare for a crack and if you flared the line check to see if the double flare is off center.

A.Delaney

It's leaking between the MC and the adapter. I'll pull it apart and check it again.

xpndbl3

iTrader: (5)

I didn't use the fittings that came with the master since you had to flare a brake line to use them. Instead I bought adapters and used the existing stock line fittings

A.Delaney

I tried finding adapters for the stock lines with no luck. The factory fitting are 10mmx1.5 pitch. The thread is very coarse. All I could find was 10mmx1.0 pitch which is standard for a metric brake line. All the parts stores I went to had never seen such a thing. I cut the fitting off and installed a 3/8-24 fitting. Flared the lines and threaded them into the tee.

I did get my leak fixed. I bought a new 1/2-20 adapter. I compared the tapered flares. The original adapter appeared to have a longer taper which may have been bottoming out in the M/C port. I swapped them out and all seems fine so far.

red406

iTrader: (4)

I wanted to give an update to my conversion.

I have had some issues with my manual brake swap. The pedal was soft and took 2-3 pumps to get a solid pedal. I fought with this for a while. I bled the brakes several times. Finally I used a temp gun and checked rotor temperature after a short trip around the block. I found the rear rotors were around 170* and the front were at 109*. This was on a 90* day. I started looking at the front brakes, because it seemed like the front calipers were not working.

I was doing some reading on the Internet. I found out that GM used "low drag" calipers and "step bore" master cylinders in most rear wheel drive cars in the '80s. When you mismatch these components expect to have problems. I bought some "2.75 inch big bore" metric calipers by Afco from Summit Racing. They bolted on perfectly. My car stops great now and is a pleasure to drive.

FRMULA88

I started the swap over the weekend.

I bought the JEGS kits but then realized it had the 1.125 bore master cylinder... which I think will be too big for my single piston front disc / rear disc. I have the SSBC big bore front calipers, and wildwood rear calipers.

I picked up a 1.030 bore master cylinder from Strange Engineering (about 10 minutes from my house). I will keep the 1.25 M/C as a spare in case I decide to update the front brakes to 4 piston.

The hardest part was working under this dashboard! I am 6'3
So I removed the steering column and that gave me a ton of room to work.

I took the brake pedal out, drilled the new pushrod hole, no clearance issues with brake switch mounting plate.

All I have left to do is re-route the brake lines to the master cylinder.

I am going to retain my OEM proportioning valve because it has the provision to install the "brake" idiot light which I think is nice to have because if something goes wrong (ie. low fluid /leak) the light comes on.

Also when I use my line lock the light comes on until I disengage the line lock.

I will move the prop. valve closer to the strut tower, retaining it should also make re-plumbing to the master cylinder much easier since I only need to rework 2 lines.

Amazing how much room this mod. created, with the vacuum booster gone and the master cylinder tucked to the firewall getting to #5 & #7 spark plugs will be a breeze! even without having to re-work all the brake lines.

The reason I don't want to screw with my lines is because I replaced them all 2 years ago with CNC bent stainless steel.


Once I have the engine re-installed and the drivers side header pipes on I can decide if the brake lines are going to be in my way, so I can fine tune it at that point. I could get to #5 with power brakes, it was a hassle with master cylinder so close. However #7 was the worst plug to service because the header pipe and vacuum booster made access a PIA, I had to jack the car up and do it from underneath .

I will post some pictures.

FRMULA88

tada!

stage20

iTrader: (3)

id get rid of the booster bracket on the dist block and then carefully bend the block down out of the way. looks like you got a clean ride man. anymore pics?

FRMULA88

I will remove the bracket with a cutoff wheel.
I replaced all the original hard lines 2 years ago with pre-bent stainless,
so trying to bend the block is harder than it sounds.

I should have plenty of room now to get my hands in & replace #5 & #7 spark plugs without dislocating my wrists or crawling under the chassis.

Once I have the engine re-installed and the headers on I can see if I need more space for access, then I can tweak the block position.


some eye candy

FRMULA88

11.13 @ 121.37 MPH

should be in the tens once I sort some matters out.

FRMULA88

I vacuum bled all the lines, and then re-did it the old fashioned way with a helper just to make sure. better safe than sorry.

I was surprised how much air was in the system, but it is all purged now.

The brake pedal feels great, the rotors grab nice and firm, you cannot turn the wheels by hand until you release the brake pedal.

so far so good, now I just need my motor back !

krazeefewl

iTrader: (1)

I have a few questions for anyone who is willing to answer them.

Is anyone running 6piston up front and 4 in the back?
If so what setup do you have and how does it feel?

Does anyone know of a replacement reservoir that looks a little better than the black ones that all of these seem to come with?

FRMULA88

Check out Wilwood, they make a M/C with a billet reservoir


M/C bore size is determined by # & size of brake pistons / wheel cylinders.

The larger the size and quantity (area) the more M/C bore you need to apply sufficient fluid pressure.


rule of thumb

bigger bore = more piston area

smaller boor = less piston area

My suggestion would be to contact Wilwood or Strange or browse their website to get pointed in the right direction. it would help if you know the bore area of the caliper pistons or at least the brand model #

this will get you in the ballpark.

My guess is you will need 1.125 bore minimum, but that is just my guess

FRMULA88

http://www.strangeengineering.net/


go to page 110 of their catalog.

they offer 2 sizes... 1.032 & 1.125

krazeefewl

iTrader: (1)

Thanks, looks like I will be making some calls. I'll be using the C6 Z06 brakes on mine, just seeing if anyone else who is running those has manual brakes.

JesasaurusRex

iTrader: (3)

i JUST ordered this kit here, today. Seemed the cheapest for what i needed to convert. Kinda scared to get the 1.125" bore MC over the 1.03x after reading all the horror stories over here. As somebody pointed out you can buy a kit with the 1.03x bore size here if need be. $50 bux more, but if it's right it's right. I have 4 piston calipers in the rear however and just ordered some 4 piston caliper fronts to go with this. Will keep posted (don't expect another post for a few months haha)

xpndbl3

iTrader: (5)

1.125 is perfect with four piston calipers front and rear. When you rolling through my town again jesse?

JesasaurusRex

iTrader: (3)

I was just in schaumberg actually 2 weeks ago , for 2 months lol. I was gonna call ya but I was pretty busy. Back in WI right meow

Slush92RS

iTrader: (6)

I'm in this process, but it seems every kit comes with the 1.125 M/C, does anyone sell the conversion kit using the smaller 1.03 M/C. I've read through this entire post several times trying to get all the best info, and ive shopped all the sites looking for the cheapest route. It appears I may have to piece this whole thing together in order to get the right M/C.

Any help is appreciated, TIA

1BADRZ28

iTrader: (2)

I pieced mine together and built the firewall bracket. I used the largest MC with drums in the rear and it worked fine. Still worked when I converted to disc.

KWIK84

iTrader: (5)

1.125" Chrysler MC with Stock front calipers, and single piston rear calipers, Hole drilled 1" up from stock. Best pedal feel and stopping power it has ever had. Feels just like the power brakes on my DD.

ProfessorStarks

I used my stock M/C. I simply took the stock unit apart, then drilled and tapped the piston. I disassembled my booster and reused a couple seals, along with the pedal rod and threaded it. Lastly, I made a mounting bracket out of 3/8" aluminum flat bar. I also purchased some stainless steel carriage bolts from Lowes (same thread as stock mounting bolts to reuse the original lock nuts). Other than bolts and brake fluid I didn't have anything hardly invested except a few hours of my time.

stage20

iTrader: (3)

stainless steel carriage bolts are VERY SOFT grade stainless. i would thing that a 3/8 bolt wouldnt break, but i would never use them for a braking application.