25 Master Cylinders (1 Viewer)

[foxfab]

I'm in the process of rebuilding the wheel cylinders. Most were stuck. I'm working 12 hour nights so its a slow process in between sleep, family, and work I swapped on a known good master cylinder and I still had the pedal go to the floor so its gotta be adjustment and stuck wheel cylinders. I should have it buttoned up tomorrow.

 

[My wife said no FJ!]

 

[foxfab]

I never followed up on this post. Properly adjusting the brake shoes fixed the problem after all hydraulics were functioning properly.

 

[Splangy]

Update:

The Raybestos MK166 kit works on the FJ25 brake and clutch master cylinders. It's intended for 1950's Fords, but is very similar to the internals of the FJ25 master cylinders.


Best of all - it's only like $11 at rockauto.com

 

[Living in the Past]

Thanks you that is great info to know.

 

[treerootCO]

Raybestos MK166 is no longer available (all webpages show 1 in stock so we know that no one can actually get one). We ran into that trying to find Fj40 domed pistons. I do see a Dorman part number 3600 for 1" wheel cylinders. Anyone have a part number that I can order?


1953 FORD F-100 3.5L 215cid L6
Click to Jump to This Part Listing in the Part CatalogBrake/Wheel Hub : Wheel Cylinder Repair Kit
DORMAN Part # 3600
Rear Right; Bore: 1 In.
Rear Left; Bore: 1 In.

 

[Splangy]

The Raybestos MK166 should cross to the AC Delco 18G1226 kit. I used the Napa part number that Jim provided in the part number thread for the wheel cylinder cups.


...via IH8MUD app

 

[treerootCO]

Adding value where I can.... Fj25/Fj25L microfiche

 

[treerootCO]

Parts on order - I found a B2937 on the wheel cylinder so I know that works well

Wheel Cylinders:
DORMAN 1499 Drum Brake Wheel Cylinder Cup $ 0.34 each

DORMAN B2937 Drum Brake Wheel Cylinder Boot $ 0.53 each

ordered both to compare:
RAYBESTOS MK166 Master Cylinder Repair Kit $ 6.44 each
ACDelco 18G1226 Master Cylinder Repair Kit $18.91

 

[treerootCO]

started polishing the 25 cylinders... honed, 600grit, 1200grit, 2000grit, 3000grit, and then metal polish.

 

[treerootCO]

Here is the break down of the FJ25 brake Master Cylinder. The big nut on the end is 38mm or 1.5".

The internals appear to be original as the rubber cups are marked TEQ.

Clutch Master:

Brake Master:

 

[treerootCO]

I don't think the Raybestos and/or AC Delco kits will work with the FJ25 Mater Cylinders. Does anyone have a different part number I can try?

I was able to confirm the AC Delco and Raybestos kits are exact even down to the part numbers.

 

[treerootCO]

Here is the Raybestos/ACDelco compared to the FJ25 and the early FJ40 with the Tin Can. I took four apart and didn't see a difference but I may have just found 4 cllutch masters because these didn't have any check valves in them.

If you look at the early 40, I am thinking the boot can be swapped over to the FJ25 piston. This one looked pretty good so I may just try that.

The wheel cylinders are figured out.

Wheel Cylinders:
DORMAN 1499 Drum Brake Wheel Cylinder Cup $ 0.34 each

DORMAN B2937 Drum Brake Wheel Cylinder Boot $ 0.53 each

 

[treerootCO]

Clutch - added inline above to make it easier to compare

 

[treerootCO]

OK...here is a dilemma. I kept everything separate until I thought I was good. Then I realized that the brake and clutch pistons are a different length. Based on my logic... I would think the longer one goes in the clutch to make up for the valve that only the brake has. What are your thoughts? Has anyone run into this yet?

 

[treerootCO]

Ok, I put it all back together. I put the smaller piston in the brake and used the rubber from the new pistons on the old pistons. From Raybestos MK166/AC Delco 18G1226/Napa 166 kits I used the following:

Clutch:
Piston rubber
1" cup
Spring
Rubber grommet

Brake
Piston rubber
1" cup
Spring
Valve
Rubber grommet

 

[JohnnyC]

great write up!!

 

[Aussie 25]

OK...here is a dilemma. I kept everything separate until I thought I was good. Then I realized that the brake and clutch pistons are a different length. Based on my logic... I would think the longer one goes in the clutch to make up for the valve that only the brake has. What are your thoughts? Has anyone run into this yet?

View attachment 960885

Thats interesting because the parts manul says PN 44351-11 fits both cluch and break master.
I am getting bits ready to rebuild a copple as well, i will look at the kits i have.

 

[KY Longhunter]

REAL TIME HELP! I just bought a M/C Rebuild Kit from Kurt @ CruiserOutfitters to repair my Clutch Master Cylinder on a 1962 FJ40. I removed internals, replaced everything and nada. Can't get any pressure in the line??? Im ready to bang my head on wall.

Any secrets to priming the Master Cylinder?

 

[KY Longhunter]

REAL TIME HELP! I just bought a M/C Rebuild Kit from Kurt @ CruiserOutfitters to repair my Clutch Master Cylinder on a 1962 FJ40. I removed internals, replaced everything and nada. Can't get any pressure in the line??? Im ready to bang my head on wall.

Any secrets to priming the Master Cylinder?