Brake Master Cylinder Alternatives?

Buddy

Buddy

Well-known member
Nov 6, 2006
2,839
1
Central NC
I looked at my master cylinder the other day and the reservoir has a bunch of cracks in it. I do have a spare reservoir from a different truck that's almost new and there is a MC on my parts truck that I could potentially use. But I've read that it's hard to get the reservoirs to seal properly if you try to replace them, and I'm not too sure about the condition of the MC on the parts truck. So I was doing some searching on alternatives to the DI ABS MC. I did see one post where someone said they used a D90 MC on their DI, but it didn't go into specifics.

The D90 MC seems to be slightly cheaper than the DI and it looks like the design might be less likely to leak. I've removed the ABS from my truck and have non-rover front brakes anyway so I don't see the need to stick with the ABS compatible MC.

Has anybody swapped out the DI MC (STC1284) with a D90 (STC441)? Any thoughts or experiences? Any other options out there?
 
Buddy

Buddy

Well-known member
Nov 6, 2006
2,839
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Central NC
ptschram said:
I sent you a PM, however, if you're at that point in the build, I might have something done by the time you're ready.

I've had a Strange master cylinder bouncing around the shop.
Click to expand...

I'm in the process of doing an axle swap. So once that's done I'll have to see how the brakes work. But the front calipers are huge. So I might need to look at upgrading the rear which is still using the DI rear caliper. At which point I'm not sure if the DI MC will be able to keep up.
 
Buddy

Buddy

Well-known member
Nov 6, 2006
2,839
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Central NC
I think I might have found a solution. Decided to try the MC off of a 2003 Durango. It has a 1 1/8" size bore and is readily available at your local parts store. I had to remove the small lip from the hole on the booster and make an adapter. I'll also need to lengthen the push rod about 3/4". But otherwise I think it will end up working. I won't really know until I finish the axle swap and update the brake lines. So it will be a while still. But I'm feeling optimistic.

I decided to put DI front calipers on the rear axle so I'll be running 2 piston D60 fronts and DI fronts in the rear. Should hopefully be plenty of stopping power for the 37's.

2DC35A8E-6957-4EDB-97DD-E855118F7BA1.jpg

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WILL.TILLERY

WILL.TILLERY

2
Apr 20, 2004
6,928
226
Floyd, Virginia
I have a few solid new units in stock... They will not rust and peel up like the earlier ones. They come with a 3 year warranty and are only 150 if interested.... its the complete MC and Reservoir.
 
Buddy

Buddy

Well-known member
Nov 6, 2006
2,839
1
Central NC
WILL.TILLERY said:
I have a few solid new units in stock... They will not rust and peel up like the earlier ones. They come with a 3 year warranty and are only 150 if interested.... its the complete MC and Reservoir.
Click to expand...

Thanks Will, the issue is more with the size of the stock one. Once you upgrade the brakes to ones that have much larger volume the stock MC is woefully inadequate. On the donor truck that the axles came off of the pedal would go almost to the floor and felt spongy.
 
fishEH

fishEH

Well-known member
Jan 26, 2009
6,930
203
Lake Villa, IL
Tobias, how'd you mount the D1 front calipers in the rear? They don't bolt right up, do they?
What are you doing for a proportioning valve?
 
Buddy

Buddy

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Nov 6, 2006
2,839
1
Central NC
fishEH said:
Tobias, how'd you mount the D1 front calipers in the rear? They don't bolt right up, do they?
What are you doing for a proportioning valve?
Click to expand...

No they don't bolt up. The mounts are 3/8-1/2 farther apart. Still working out the details. I've test fitted them to make sure they line up. Having the spider trax housing helps. I'm cutting and modifying the current mounts to lengthen them.

I'll be running a Wilwood adjustable proportioning valve. I'll post updates as I get farther into it. But updates might be slow since this project is really dragging out.

This is the one I ordered.
Wilwood 260-11179 Proportioning Valve https://www.amazon.com/dp/B003LT619Q
 
lunchbox

lunchbox

Well-known member
Apr 20, 2004
2,139
166
50
St Louis, MO
Brett

I put fronts in the back of my truck once. The mc just couldn't keep up with the volume. All I did was oval one hole. I think I still have them if you want to mess with the set up. Maybe the MC Tobias is trying out will help. I also used the stock prop valve, and ran all new lines without the abs.

Buddy,

The brakes worked fine until the guy on loading it here cut one. I had those new soft lines made local. Maybe they just need a good bleed? But you're right, those front calipers are giant.
 
Buddy

Buddy

Well-known member
Nov 6, 2006
2,839
1
Central NC
lunchbox said:
Brett

I put fronts in the back of my truck once. The mc just couldn't keep up with the volume. All I did was oval one hole. I think I still have them if you want to mess with the set up. Maybe the MC Tobias is trying out will help. I also used the stock prop valve, and ran all new lines without the abs.

Buddy,

The brakes worked fine until the guy on loading it here cut one. I had those new soft lines made local. Maybe they just need a good bleed? But you're right, those front calipers are giant.
Click to expand...

From looking at them I would agree ovaling them should work. I can see the start of the second bolt hole when the first bolt is in.

I had considered that bleeding them might help. But since I was putting larger calipers in the rear as well as reworking all the lines. I figured I'd get some more volume in the system.
 
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Buddy

Buddy

Well-known member
Nov 6, 2006
2,839
1
Central NC
Got the adapter plate finished, extended the push rod and started to plumb up the proportioning valve. Too bad I won't be able to test it until I finish the axle swap.

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Trevor

Trevor

Active member
Mar 21, 2016
29
0
NE PA USA
Buddy said:
These are the front calipers.
9D5D188D-3C45-49F6-9BC6-F40E7F22AC9D.jpg
Click to expand...
they are the same fronts I will be running. Mostly posting up to keep a eye on your progress. I am big into 73-89 chevys so I already started to think about what I may have on the shelf. Hydro master maybe? I wasa already looking at putting a p-pump in so the rest of a hydro would cake


on a side note my old tube buggy with chevy tons and 4Ds had two manual brake masters (wildwood race pedal setup) and it stopped the rig great, even down the road. I was worried at first since I had a ton of rotating mass, steel spacers, H1's with rings, pitbull rockers. But I plan on being more road legal-ish with the disco
 
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