montanaman
NAXJA Forum User
- Location
- Western Montana
Hey ... for those of you who have Clutch MC and slave with the push-in style of plastic clutch line, it's easy to change out. If you're sick of the plastic crap, you can easily tap the line port to 1/8" NPT Female threads.
General directions:
- Disassemble the MC or slave. There is usually some sort of circlip where the action rod comes out of the cylinder. Remove that clip, and everything will come right out ... the MC is under spring pressure, so be careful.
- Get all the internal parts out and lay them on a clean rag in the order they came out.
- Clean the main bore thoroughly.
- The port for the hydraulic line is a "smooth bore" port. The line pushes in with an o-ring to seal it (which already sounds bad) and a roll pin to hold it in place (even worse).
- Tap out the line port with a 1/8" NPT tap. There is a "lip" about 1/2 way down the outlet port. That lip stops the old-style push-in connector from going further down. Ignore this lip ... it's not big enough to interfere with your tap. There is also a cross-way hole where the roll pin hods the push-in connector. Ignore that cross hole. Your NPT adapter will go past that and seal it off. In short ... just tap the port.
- Clean ALL metal (or plastic) shavings from the cylinder ... give it a good bath in brake fluid.
- Reassemble the internal parts into Cylinder in the order they came out. It's very straightforward.
- Get an adapter that allows you to screw in a brake fitting to the 1/8" Female NPT opening in your cylinder. They are very common, and most auto parts stores have them.
- Wrap the male NPT threads of the adapter with plumber's PTFE thread tape, and screw the adapter into your cylinder.
- Get a generic brake line of the proper length and bend it to match your old plastic line ($5 solution) ... OR get a hydraulic clutch line for '90 XJ with your kind of transmission (for the AX15, it's Dorman Part# H38938 -- $20+). This will allow you to toss your plastic line with the push-in connectors.
- Thread your new hard line it into your new threaded ports on your cylinders and you are good to go (bleed thoroughly).
- You may ask why NPT ... why not tap to the thread size of your brake line fitting? Well that won't work, because the port coming out of the MC has no "bottom" to it to seal the brake line fitting. It's just an ordinary round hole going down into the main bore of the cylinder. The only way to get threads into that is tapered NPT, which can give a solid "Pipe" style of seal. All high-end racing brake and clutch MCs come with 1/8" NPT female threads for line connections. The adapter will have the proper style of female-thread fitting for your brake lines.
Additional directions for Internal slave cylinders:
- I don't know if internal slaves can be disassembled like this ... I haven't tried it yet, but it might be possible. The instructions above are for external slaves and MCs.
- But ... internal slaves have a metal line coming out with a threaded brake fitting on the end of it. Some years (like '91 and '92) have the "quick disconnect" (f**king disaster) attached to the brake fitting on the end of the line coming out of the slave. Unscrew that and set it aside. Make a Christmas tree ornament out of it.
- That will leave you with an internal slave with a male-threaded brake line coming out of it. Buy a "Brake line union" adapter that will allow you to join the male-thread slave line to the male-thread MC line. Those union adapters are very common, and most auto part stores carry them for a few bucks.
Hope this helps.
General directions:
- Disassemble the MC or slave. There is usually some sort of circlip where the action rod comes out of the cylinder. Remove that clip, and everything will come right out ... the MC is under spring pressure, so be careful.
- Get all the internal parts out and lay them on a clean rag in the order they came out.
- Clean the main bore thoroughly.
- The port for the hydraulic line is a "smooth bore" port. The line pushes in with an o-ring to seal it (which already sounds bad) and a roll pin to hold it in place (even worse).
- Tap out the line port with a 1/8" NPT tap. There is a "lip" about 1/2 way down the outlet port. That lip stops the old-style push-in connector from going further down. Ignore this lip ... it's not big enough to interfere with your tap. There is also a cross-way hole where the roll pin hods the push-in connector. Ignore that cross hole. Your NPT adapter will go past that and seal it off. In short ... just tap the port.
- Clean ALL metal (or plastic) shavings from the cylinder ... give it a good bath in brake fluid.
- Reassemble the internal parts into Cylinder in the order they came out. It's very straightforward.
- Get an adapter that allows you to screw in a brake fitting to the 1/8" Female NPT opening in your cylinder. They are very common, and most auto parts stores have them.
- Wrap the male NPT threads of the adapter with plumber's PTFE thread tape, and screw the adapter into your cylinder.
- Get a generic brake line of the proper length and bend it to match your old plastic line ($5 solution) ... OR get a hydraulic clutch line for '90 XJ with your kind of transmission (for the AX15, it's Dorman Part# H38938 -- $20+). This will allow you to toss your plastic line with the push-in connectors.
- Thread your new hard line it into your new threaded ports on your cylinders and you are good to go (bleed thoroughly).
- You may ask why NPT ... why not tap to the thread size of your brake line fitting? Well that won't work, because the port coming out of the MC has no "bottom" to it to seal the brake line fitting. It's just an ordinary round hole going down into the main bore of the cylinder. The only way to get threads into that is tapered NPT, which can give a solid "Pipe" style of seal. All high-end racing brake and clutch MCs come with 1/8" NPT female threads for line connections. The adapter will have the proper style of female-thread fitting for your brake lines.
Additional directions for Internal slave cylinders:
- I don't know if internal slaves can be disassembled like this ... I haven't tried it yet, but it might be possible. The instructions above are for external slaves and MCs.
- But ... internal slaves have a metal line coming out with a threaded brake fitting on the end of it. Some years (like '91 and '92) have the "quick disconnect" (f**king disaster) attached to the brake fitting on the end of the line coming out of the slave. Unscrew that and set it aside. Make a Christmas tree ornament out of it.
- That will leave you with an internal slave with a male-threaded brake line coming out of it. Buy a "Brake line union" adapter that will allow you to join the male-thread slave line to the male-thread MC line. Those union adapters are very common, and most auto part stores carry them for a few bucks.
Hope this helps.
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