Master cylinders for 64 J300

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64_Gladiator
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Joined: Mon Jan 21, 2019 1:16 pm

Master cylinders for 64 J300

Post by 64_Gladiator »

Hi all,

New member, I picked up a 64 F300 (rather saved from a junkyard). Its an odd ball we are trying to rehab. Its got a 350 Olds motor with a 4spd. We are trying to get it mobile to sort out some other items. The motor is up and running but the clutch master cylinder is leaking. There are tons of new clutch cylinders with slaves for modern jeeps but nothing out there in the early 60's. Is there a source for these or is swapping a new style acceptable? I have seen discussion of upgrading Kaisers but not much for what I'm working with.

Thanks!
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Cecil14
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Re: Master cylinders for 64 J300

Post by Cecil14 »

It's probably a Buick 350, not Olds (unless someone swapped it in?). Trans should be a T98.

I believe Napa still has availability for the 60s clutch masters. Go to a store and have them pull out the book. They have a house brand that still offers what you need, or did until very recently at least.


aa
1983 J-10 - 4.6L(MPFI)/CS130D/Hydroboost/NV3550/D300/44/44/3.54/Disc-Disc/32s/42 gallon 'burb tank
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tgreese
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Re: Master cylinders for 64 J300

Post by tgreese »

I would guess it was originally a 230 engine, since that's the model that had a hydraulic clutch. Swapped V8.

Zack shows a rebuild kit 932332 for that cylinder http://stores.zmjeeps.com/master-cylinder-kit-932332/

The part number for the complete cylinder is 925373, but I did not find anything for that.
Tim Reese
Maine beekeeper's truck: '77 J10 LWB, 258/T15/D20/3.54 bone stock, low options (delete radio), PS/PDB, hubcaps.
Browless and proud: '82 J20 360/T18/NP208/3.73, Destination A/Ts, 7600 GVWR
Copper Polly: '75 CJ-6, 304/T15, PS, BFG KM2s, soft top
GTI without the badges: '95 VW Golf Sport 2000cc 2D
Dual Everything: '15 Chryco Jeep Cherokee KL Trailhawk, ECO Green
Blockchain the vote.

Topic author
64_Gladiator
Posts: 4
Joined: Mon Jan 21, 2019 1:16 pm

Re: Master cylinders for 64 J300

Post by 64_Gladiator »

Cecil14 wrote:It's probably a Buick 350, not Olds (unless someone swapped it in?). Trans should be a T98.

I believe Napa still has availability for the 60s clutch masters. Go to a store and have them pull out the book. They have a house brand that still offers what you need, or did until very recently at least.


aa
Thanks for the Napa tip! But sigh it is a swapped in Olds rocket. A golden rocket :banghead:

Topic author
64_Gladiator
Posts: 4
Joined: Mon Jan 21, 2019 1:16 pm

Re: Master cylinders for 64 J300

Post by 64_Gladiator »

tgreese wrote:I would guess it was originally a 230 engine, since that's the model that had a hydraulic clutch. Swapped V8.

Zack shows a rebuild kit 932332 for that cylinder http://stores.zmjeeps.com/master-cylinder-kit-932332/

The part number for the complete cylinder is 925373, but I did not find anything for that.
It was an I6 as far as we know. Is there any utility in upgrading to a newer cylinder or just call it good and buy the ZM rebuild kit if Napa can't find a complete unit?
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tgreese
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Re: Master cylinders for 64 J300

Post by tgreese »

I don't think there's any functional advantage to a different cylinder, even if more modern. My preference would be 1) a new replacement cylinder of the same type (a replacement 925373), 2) rebuild the old cylinder if the bore is not rust pitted, 3) adapt some kind of more modern cylinders.

Hydraulically, the only consideration is the diameter of the two cylinders. If I made modern parts work, I'd look for a master cylinder and slave cylinder with the same cross-section area ratio. That would provide the same travel and mechanical advantage as the original parts.
Tim Reese
Maine beekeeper's truck: '77 J10 LWB, 258/T15/D20/3.54 bone stock, low options (delete radio), PS/PDB, hubcaps.
Browless and proud: '82 J20 360/T18/NP208/3.73, Destination A/Ts, 7600 GVWR
Copper Polly: '75 CJ-6, 304/T15, PS, BFG KM2s, soft top
GTI without the badges: '95 VW Golf Sport 2000cc 2D
Dual Everything: '15 Chryco Jeep Cherokee KL Trailhawk, ECO Green
Blockchain the vote.
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tgreese
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Location: Medford MA USA

Re: Master cylinders for 64 J300

Post by tgreese »

Also, the J-series parts book is on-line here - http://oljeep.com/edge_parts_man.html You can check the part numbers yourself.
Tim Reese
Maine beekeeper's truck: '77 J10 LWB, 258/T15/D20/3.54 bone stock, low options (delete radio), PS/PDB, hubcaps.
Browless and proud: '82 J20 360/T18/NP208/3.73, Destination A/Ts, 7600 GVWR
Copper Polly: '75 CJ-6, 304/T15, PS, BFG KM2s, soft top
GTI without the badges: '95 VW Golf Sport 2000cc 2D
Dual Everything: '15 Chryco Jeep Cherokee KL Trailhawk, ECO Green
Blockchain the vote.

Topic author
64_Gladiator
Posts: 4
Joined: Mon Jan 21, 2019 1:16 pm

Re: Master cylinders for 64 J300

Post by 64_Gladiator »

Thanks! I do have that PDF which is amazing. I still couldn't find anything for new/RB cylinders. However, the rebuild kit is a great find so thank you. Regarding upgrading, I was more asking since each car niche has its own tips and tricks and thought people may have swapped to newer style master cylinders. Obviously there is no high performance here but improved seals and fluid check/fill would be an improvement as well as being able to source a replacement everywhere. Like you said it would come down to matching the volume of fluid per stroke and/or swapping the slave too.

I will start with the rebuild kit unless I have bad pitting inside.
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tgreese
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Re: Master cylinders for 64 J300

Post by tgreese »

Glad I could help. I used to work parts counter and have quite a lot of experience finding things in the books. There is an alphabetic listing at the front of the book. I found the item under "cylinder" in this index (it helps to know what Jeep calls things). I also know that Group 5 is clutch parts, so I could have leafed through the listing - it's a short section. The rebuild kit is a few lines down in the listings from the replacement part.

Once you have the part number, you can search the internet and often get an exact match.

Another route to consider is having the cylinder rebuilt professionally. For a price, the rebuilder can reline the bore with a steel sleeve and remanufacture with the rebuild parts. Check Hemming's Motor News or online for cylinder rebuilders, if interested.
Tim Reese
Maine beekeeper's truck: '77 J10 LWB, 258/T15/D20/3.54 bone stock, low options (delete radio), PS/PDB, hubcaps.
Browless and proud: '82 J20 360/T18/NP208/3.73, Destination A/Ts, 7600 GVWR
Copper Polly: '75 CJ-6, 304/T15, PS, BFG KM2s, soft top
GTI without the badges: '95 VW Golf Sport 2000cc 2D
Dual Everything: '15 Chryco Jeep Cherokee KL Trailhawk, ECO Green
Blockchain the vote.
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Stuka
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Re: Master cylinders for 64 J300

Post by Stuka »

Wasn’t the stock master cylinder in 64 a single reservoir? If so, I would not even attempt to rebuild it. I would want the safety of a dual reservoir.

But it would not be a bolt in afair.
2017 JKU Rubicon
Pevious Jeeps: 1981 J10, 1975 Cherokee, 2008 JK, 2005 KJ, 1989 XJ
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tgreese
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Re: Master cylinders for 64 J300

Post by tgreese »

This is for the clutch. But yes, the factory brake master cylinder is a single circuit. So is the clutch! :)
Tim Reese
Maine beekeeper's truck: '77 J10 LWB, 258/T15/D20/3.54 bone stock, low options (delete radio), PS/PDB, hubcaps.
Browless and proud: '82 J20 360/T18/NP208/3.73, Destination A/Ts, 7600 GVWR
Copper Polly: '75 CJ-6, 304/T15, PS, BFG KM2s, soft top
GTI without the badges: '95 VW Golf Sport 2000cc 2D
Dual Everything: '15 Chryco Jeep Cherokee KL Trailhawk, ECO Green
Blockchain the vote.
User avatar

Stuka
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Posts: 11789
Joined: Thu May 12, 2011 5:53 pm
Location: CA
Contact:

Re: Master cylinders for 64 J300

Post by Stuka »

tgreese wrote:This is for the clutch. But yes, the factory brake master cylinder is a single circuit. So is the clutch! :)
Oh slave cylinder, got it!
2017 JKU Rubicon
Pevious Jeeps: 1981 J10, 1975 Cherokee, 2008 JK, 2005 KJ, 1989 XJ

Joodan24
Posts: 13
Joined: Tue Nov 14, 2017 6:54 pm

Re: Master cylinders for 64 J300

Post by Joodan24 »

Omix-ada makes a replica of these master cylinders. I put one on my 64 and im very happy with it. Also, you can get a rebuild kit for 20 bucks and it's very easy to rebuild. I just lightly honed the bore, painted it up (rustoleum makes a hammered iron paint that looks super close to factory) and put the rebuild kit in.
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Cecil14
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Re: Master cylinders for 64 J300

Post by Cecil14 »

Anything by Omix-ada should be avoided at all costs. Their quality control is in the toilet.


aa
1983 J-10 - 4.6L(MPFI)/CS130D/Hydroboost/NV3550/D300/44/44/3.54/Disc-Disc/32s/42 gallon 'burb tank
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