My 1988 B2200 is losing clutch fluid, was below the minimum level, and I cannot yet find the leak. I checked the slave cylinder, the two flexible lines, the steel lines, and the clutch master, even scrutinizing the firewall at both the engine and driver side to look for a leak, couldn't find leak. I don't know if the firewall is double panel and fluid could leak into a cavity (like brake fluid can on an old VW). I've had clutch masters leak before, so my firewall area paint is long gone.

I added fluid, cleaned up the engine firewall surface there, will keep an eye on level and check for leaks; pedal and clutch operation feels normal.

In the 28 years I've owned my 1988, I've swapped out the clutch master and slave cylinders about 6 times, though not since 2011. I've also replaced both clutch flexible lines exactly once each. I flush completely with every hydraulic repair. In January 1997 I bought lifetime warranty clutch master and slave cylinders from an independent shop which was bought out by CarQuest and later by Advance Auto; Carquest handled the warranties but the last time a woman manager said "no more", but then they were bought out by Advance, so haven't tried them yet for a warranty replacement.

So unless someone here has a theory where the leak could be, or I find something with a month or so, I'll likely just replace both cylinders again.

 

I took a better look this morning, even swapped down the pushrod area underneath the dash with a Q-Tip, didn't see leakage there. I went underneath and I had added silicone glue a few years ago to the slave cylinder boot, and can most likely confirm a very slight leakage there; the boot was not full of fluid. With driving to dinner last night, did not see a drop in the level in the MC reservoir. So I have time to get to place 100 miles away next week to see if I have new slave cylinder there and pick up my receipts from CarQuest to try Advance for replacement. If Advance refuses, will use closer Autozone, as two women at local O'Reilly disagree with company policy on "Limited Lifetime Warranty" (which means original purchaser and original vehicle) and not their discretion to try to show their "authority". In the "big city" more recently, O'Reilly gave me zero issues swapping out a Limited Lifetime Warranty fan clutch, but was a man behind the counter.....

 

I just checked my online orders at RockAuto (you folks likely thought I was too computer-stoooopid to do this) and I did buy a closeout B2200 slave cylinder in 2012 for $5.62, so that should be in a box at my other place when I go there next week.

 

OK, got under the B2200 today. I unbolted the slave cylinder from the transmission case, leaving the fluid line intact. I pulled off the torn/silicone-glued boot off saw essentially no fluid leak there, cleaned up the pushrod, and installed a spare new slave cylinder boot that I had. Then I re-bolted the slave cylinder back on, fluid in reservoir same as when I started this thread, OK for now.