Removing tight hydraulic line from slave cylinder

[mlipmd]

Sorry if some of you on here see this as a duplicate post as I put this on the ZR-1 section of the Corvette Forum also but got no responses, so I thought I'd put it up here.
I needed to replace my clutch slave cylinder on my '90 and before tackling this job, I did a massive amount of research first on the Corvette Forum, , on ZR-1.net, other 'vette forums, YouTube, etc. I got the front of my car elevated 10" off the ground which lets me snake in from the driver's side for access. One handedly, because of no room in between the components, I managed to remove the slave cylinder but had absolutely no way to access the fitting on the hydraulic line going into the top of the slave. I thought I would get that apart after I was able to drop the slave down with the line attached. That nut is on REALLY TIGHT. I had it soaking in PBBlaster which so far has not helped. My fitting is a 13mm and regular 6 sided wrenches have failed to budge it. I have on order some metric flare nut wrenches to get a better grip on it and try and avoid rounding off the nut, but are there any other suggestions to break this loose and also not damage the line itself? Can I heat this up with a torch or a heatgun to try and loosen it? I really don't want to bugger up that fitting and then have to replace the whole hydraulic line, another major PIA taking everything apart to do that.
Maybe I should put my old slave back on the studs on the bell housing and try again, but I don't want to even think about breaking them off either.
I can't believe anyone would tighten that fitting so much but maybe it's from sitting there for between 25-33 years like that.
Any suggestions about the heat or anything else would be greatly appreciated.
Thanks.

[HAWAIIZR-1]

I thought you are upgrading your hydraulic line and clutch slave cylinder to later model design? If you are I would not give a hoot about damaging the line or fitting as long as you have the new style cylinder and hose on hand. The attached photo is the late model hydraulic hose that is available and hopefully you can find the good, rebuildable clutch slave cylinder. I know the cast ones are not ideal and I was fortunate enough to have Jim Jandik rebuild before he retired. If you have not already I would contact Bill B ZF Doc to see what he has or the latest best available.

[mlipmd]

Where is that screwed-on clip that holds the line to the body and how easy is that to access?

[HAWAIIZR-1]

Where is that screwed-on clip that holds the line to the body and how easy is that to access?



I?m in Hawaii and away from my 95 car to look. Without looking my guess it is bolts to the bellhousing bolt. Hopefully someone else with 91-95 can respond before I get back to my car. All I remember is the upgrade was very simple on my
90. Only NCRS people won?t want to do it.

https://www.google.com/amp/s/www.motortrend.com/how-to/repairing-clutch-long-neglected-1995-c4/amp/

https://afterdarkspeed.com/product/89-96-c4-zf-6-speed-performance-clutch-master-cylinder-kit/


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[jw63]

Where is that screwed-on clip that holds the line to the body and how easy is that to access?

https://www.zr1.net/forum/showthread.php?t=28926&highlight=hydraulic+line

[mlipmd]

If I can't find or access that clip and I can't get my fitting apart at the slave, is there any problem with just replacing the line, snaking a new SS braided line down to the slave, and leaving the old one in place? Maybe I'll just get a new rattle in the car- Ha.
How easy is it to drop a new line in place - will it come out underneath where it can be grabbed and brought over to the slave or is there a trick of routing it? If I can find and access that clip I could always tie the new line to the old as I pull the old one out, either through the top or the bottom.

[HAWAIIZR-1]

If I can't find or access that clip and I can't get my fitting apart at the slave, is there any problem with just replacing the line, snaking a new SS braided line down to the slave, and leaving the old one in place? Maybe I'll just get a new rattle in the car- Ha.
How easy is it to drop a new line in place - will it come out underneath where it can be grabbed and brought over to the slave or is there a trick of routing it? If I can find and access that clip I could always tie the new line to the old as I pull the old one out, either through the top or the bottom.

The post that JW63 shared with you explains about the old line. I think once you?re in there it?s not that difficult or at least I don?t remember having a problem with it. No need to leave the old line in there. Shoot Bill B an email or better yet, call him to see what all is involved. I?m sure he knows off the top of his head. Im surprised still no first hand experience being shared by 90 owners. I think more and more people are on Registry Facebook page so quicker response than here.

[mlipmd]

I have soaked that fitting with PBBlaster for a week and it hasn't done a thing. I used the best penetrating liquid ever, which has always worked when everything else has failed - a mix of ATF and acetone, and that hasn't worked so far either. I got my metric flare wrenches (my fitting is 13mm) and I can't budge it at all, it's like it's welded together (and after 28-33 years, it probably is). Next thing is to heat it up with a torch and see if a friend of mine who maybe is stronger than me can come for a try. Too bad Ahnold isn't around. And I know, righty tighty, lefty loosey so don't start with that.
If all fails, I guess I have to order a new hydraulic line and take the front of the car apart to change it out. I wasn't really wanting to do that but I may have no choice.
Anyone have a recommendation for a hose line covered in SS braid or should I go with a factory replica with SS tubing and rubber hose in the middle?

[mlipmd]

OK, so finally with a friend going in under the car from the front and me on the side and him pulling on the slave and me pulling on the 13mm flare wrench with another wrench as an extender on it for more leverage, I finally broke that hydraulic line fitting free from the slave. And amazing how clean it was, no dirt or rust, all threads looking brand new. Dirty little fcker for giving me so much trouble.
So now I have another problem needing help or enlightenment as to tricks for getting the slave back in.
I prefilled it with DOT4 and bleed it on the bench doing that, connected the old hydraulic line as it was dripping fluid slowly so minimizing air and bleeding of the system, but now the big problem is getting it back in place and bolting it on. I know you have to center the rod in the depression in the fork but how do you apply enough pressure to compress the slave against the spring inside and get it in place? There's either some trick to this or I am missing something basic.
I really don't want to empty the slave to try and make it easier to compress the cylinder in the slave, was wondering about applying suction at the master possibly making it easier to compress the slave.
I need ideas on how to get the slave back in.

[HAWAIIZR-1]

Glad to hear you made good progress. It has been some time since I had to replace my clutch slave cylinder, but if it were me I would be cracking open the bleeder to push it back in and close the bleeder. Then install and bolt on. Pump to get pressure and see if air bleeds from up in clutch master and follow bleed procedures to get your pedal back. Sorry, I don?t remember having much trouble, but I did convert to later model line and slave at the time. Best wishes.


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[Mikey]

I have always been able to push enough with hand to start the nuts. Even after bleeding the system first.

[mlipmd]

I got my problem resolved and my clutch back in order and am giving you guys my solution.
My Yankee ingenuity has solved my problem of how to compress the spring in the slave with very little room and leverage lying underneath the car, and getting the job done in 5 seconds with the help of someone else to assist.
Using a straightened out metal coat hanger with a small loop on the end, I pulled a length of 1/4" line through under the car, alongside the current hydraulic line (outboard of the catalytic converter and exhaust), and looped it over the hydraulic line fitting on the slave, then back underneath to the front of the car. With my significant other pulling on the two lines, she could easily compress the spring in the slave allowing me to get it into position and easily hold it there while I put the two nuts on, then tightened them up. Using an assistant like this to pull the slave into place from the front of the car made this difficult task take maybe only 5 seconds.
Then it took about 10 min to get the system bled and check for leaks.
And now all's good. I have a proper clutch now with all clean fluid inside the system.
So try this trick, it's real quick and easy, no cursing at inanimate objects, no bruised knuckles, just get someone to help and to pull it from the front.