C60X Master Cylinder rebuild kit

[Gunner]

Hi Guys:

The C60X has a large rectangular master cylinder identical to that used on the early CCKWs except that the crank arm is on the left side of ours due to the right hand drive.

Any one know where I can get a rebuild kit for one of these beasties?

Mike

[RHClarke]

Mike, What is the inner diameter of the of the cylinder? Jim Carter's in the states has rebuild kits.

Rob

[Grant Bowker]

I don't have a listing of a source for either the entire rebuilt master cylinder or rebuild kit but the manuals list the diameter as 1-3/4" (compared 1-1/4" for the Ford and Chev 15-60 cwt trucks).
I haven't done an exhaustive (or exhausting) search but www.steelsoldiers.com www.wheelsofvictory.com www.obschevy.com (Tim Tygart) www.oldchevytrucks.com (Jimmy Carter) www.chevsofthe40s.com all came blank so far. I haven't tried catalogue surfing at CarQuest or NAPA yet. Now that I have a C60X I need to start looking for sources for parts to decide about working on it.
Can anyone help with sources?

[Harry Moon]

Hi Grant
i have a little C60X project in the works too. I think I sorted out my bellhousing flywheel. i used a regular CMP bellhousing with a smaller diameter(than a CCKW) flywheel. Tryying to find out if it was a different clutch and disc than other CMP's
the tranny is different but would one of my CMP tranny' fit?
was I right that the bellhousing was the same?

[Grant Bowker]

I'm away from references until tonight, will check parts #s for the two bellhousings. From memory the clutch is 11-1/2 or 11-3/4 inch diameter for the C60X which seems larger than I remember for the C15-C60 series, this can also be checked. Do you have good sources for how close C60X is to CCKW or AxKW for engine (and transmission?) and brake system? There are two different brake booster systems listed in the parts manual (easiest to tell the version by length, early 13+ inches, late 21+ inches), but only the earlier one seems to be mentioned in the maintenance manual I have.
The next interesting puzzle will be to see what I can find out about the steering shock absorber.

[Grant Bowker]

Clutch facing diameter C60X 11-1/2"
Clutch facing diameter C60L 10-3/4"
Cluch "driven member" is same part# for CCKW, AFKWX and C60X, naturally C60L is different.

Bellhousing or clutch housing - C60X is different part# than C60L and CCKW and AFKWX, even the cover for rear of flywheel viewing is different #. The C60X bellhousing is more similar to CCKW part# series than C60L. But odd to note some CCKW minor parts in this area are common to C60L and not C60X.

Transmission - all ratios except direct (obviously) are different C60X to C60L, many specified clearances are different too. Shift pattern is different C60L to C60X. Case part# and internal parts are different C60L to C60X and also seem different to CCKW and AFKWX. The few internal parts I checked #s on were different too although the part #s suggest C60X is closer to the same series of parts as CCKW than C60L. The commercial use of the C60X transmission parts (if any) is unknown. The case and transmission assembly for the C60X unlike the C60L is marked * in the parts list, indicating CMP unique.

Master cylinder - The rebuild kit listed for the late C60X is also listed as fitting the CCW and CCKW. The rebuild kit for the early C60X doesn't appear in the Master Parts List for the CCW and CCKW. The illustration of the master cylinder for the C60X is virtually identical to the one in the GMC Master parts list for the AFWX-354, AFKWX-352 and -353 as well as CCKWX-353 and some CCKW-353 and -352. I don't know if this is a case of using an existing illustration to identify parts for a mirror image assembly due to RHD compared to LHD or if the cylinder assemblies were truly the same. Neither the complete assembly or bodies nor the input shaft for the C60X show in the GMC Master Parts List but many of the internal parts are the same. This suggests to me that the mirror image theory might be valid.

The steering shock absorber seems to share many component parts with the C60X front shock absorbers but has a separate assembly part #. This might reflect something as minor as the arm being set at a different angle for the different use...... One style of C60X front shock matches a C60L part#, but there are several other #s that don't match. The shock assembly #s are also different to CCKW and AFKWX and by the time I came to this I was not going to spend time checking individual part #s.

Sometimes, the more I look and learn, the more I realize I don't know. That's where this seems to be heading after an hour and a half in the manuals.

[Grant Bowker]

Originally Posted by Gunner

Hi Guys:

The C60X has a large rectangular master cylinder identical to that used on the early CCKWs except that the crank arm is on the left side of ours due to the right hand drive.

Any one know where I can get a rebuild kit for one of these beasties?

Mike

Good day Mike,

I just came across your posting about this on CCKW.org, did you ever find either a source for rebuild kits or the complete master cylinder? I've been doing a bit of digging lately on these master cylinders and may be able to provide some more suggestions if needed.

Grant

[Phil Waterman]

Hi Grant

Try http://vehiclesofvictory.com/ Bob and I have found some strange parts there like CMP brake boosters (I think we bought the only ones they had).

Steve Kieth who reads MLU from time to time is also known as Doctor Duce, so if you're reading Steve any thoughts on rebuild kits.

Cheers Phil

Cheers Phil

PS---- Just visited the Vehicles of Victory web page, their catalog doesn't list rebuild kits but it does look like they will rebuild and sleeve the master cylinder.

They have also done a lot of work on their web site, has some interesting resources for Chevy parts.

[Grant Bowker]

I haven't spoken with these folks to find out if they also do 1-3/4" master cylinders but they seem to have kits for 1-1/4 and 1-1/2 box type master cylinders and offer a rebuild service.
http://www.classicandexotic.com/stor...-cylinder.aspx

[Grant Bowker]

I recently bought a 1947 dated Wagner Brake parts manual, at least partly because the ebay listing showed the box type mater cylinder parts breakdown as the sample interior page.
The C60X-04 parts manual lists the early master cylinder assembly as part 5807165. This number shows up in the GMC to Wagner cross reference as being a Wagner FF-1147. Running the FF-1147 the other way through the cross reference gives an equivalent GMC part number 2111080 (which does cross back to FF-1147), but no uses for Chrysler, Diamond T, Ford, Hudson I.H.C., Nash, Pacakrd, Studebaker White or Willys.

The only civilian use I found for the FF-1147 are GMC models T-61, T-73, T-73H, T-74 and T-74H from 1936

There are a total of 28 different box type master cylinders listed that vary in terms of which side the input lever is on, piston diameter, piston style and output threadings.

GMC did use another box type master cylinder that appears to share almost all parts except the fluid reservoir with the FF-1147. The difference between the FF-1147 and the FF-1320 is that the actuating lever enters on the opposite side (left on FF-1147, right on FF-1320). In "Wagner-speak" the FF-1147 is "left hand drive", meaning that the actuating lever is on the left hand side of the reservoir, not that the assembly is used on left hand drive vehicles. The only part I saw that was different between the two assemblies was the housing, apparently the actuating shaft has a stepped diameter so the bearings are different sizes, located mirror image. for the FF-1147 the housing is part FE-349 and the FE1320 housing is FE-490. Based on some other master cylinders, the housing numbers may be cast into the housings and as a result may be seen rather than the number for the full assembly.

The FF-1320 was used on several GMC trucks, 1947 EC-350, 1941CCKWX-353, 1940 ACKWX-353, 1940-41 ACKW, 1940 AFWX-354, select S/N ranges of CCKW 1941 production (others the same year used FF1251, a much more "normal" looking master), 1940-41 CCT-350, CCT-400 CFT-350 and CFT-400, 1939 AF-450, and others back to 1936 (earliest this manual covers). Why did I list models that used the FF1320? Because they might become parts donors for someone who has a C60X housing and needs a core for rebuild of the guts of the cylinder. The rebuild kit for both types is listed as FC-5372 (contains piston cup, check valve, input shaft seal) and the working part of the cylinder assembly is FC-2879 for both (contains the cylinder bore, piston, seals, checkvalve, output fittings).

I will try to post images and scans later to try to make all this clearer for those who aren't already familiar with the box type master cylinder used on the early C60X.

There was no cross reference to the 5827591 master cylinder used with later Hydrovac equipped C60X but the 2180728 rapair kit for it crosses to FC-8422.

The wheel cylinders for all 6 positions on the C60X are listed in the C60X parts book as 91T2261, later C91T 2261 or 91T 2192. All look like Ford part numbers, no surprise there. The Ford to Wagner cross reference gives the 91T2261 = FD-4511, no mention of C91T2261 and 91T2192 = FD-4510. The FD-4511 wheel cylinder assembly, complete is described as a "standard straight bore type" with "centered inlet - slotted piston" the bore is given as 1-1/2" (matches C60X manual info), using cylinder casting FD-4510 (so there might be a typo in the cross reference table that gave 2 different cross references???) with the repair kit being FC-5379 (contains rubber piston cups and dust covers).

As an aside, the master cylinder for the other Chevrolets, 5450260, does not appear in the cross reference. Based on general shape, 1-1/4" bore, threaded push rod, removable head at output end of cylinder, staggered base mounting bolts - one possible master cylinder might be FD-4388 which crosses back to GMC parts 5450279 and 5450280. I want to emphasize that this is a possible replacement, not in any way confirmed by measurements of actual cylinders and should not be used to order parts without confirming (or an understanding dealer who will let you return if it doesn't turn out right). The theory that the FD-4388 might fit is supported by the piston assembly 5450314 crossing to FC-4878, push rod 5450076 crossing to FC-5280 and repair kit 603646 crossing to FC-3060 are all parts that apply to the FD-4388 master cylinder. GMC part numbers were taken from the Gun Tractor parts book and cross referenced in the Wagner manual.

As another aside for those working master cylinders for CMP trailers (and Fords, since the same 91T2140 part number shows for both) the cross given in the Wagner manual is FD-4572. www.rockauto.com still lists a Wagner MC4572 that looks about the right shape. www.macsautoparts.com lists 91T-2140 as available (and cheaper, but may not include the pushrod shown in the rockauto photo).