The MSG95A/731 seat's in 3 or 4 pieces on my bench, just had the seat cushion re-upholstered. The compressor pumps it up alright but it I then leaks down when I lean on it. Thinking of pumping it up and then dumping in the bath-tub to see where little bubbles come out. Is this a stupid idea?
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grammer seat leakdown
- Thread starter towbar
- Start date
stinky64
Senior Member
- Joined
- Feb 25, 2017
- Messages
- 943
- Location
- java center ny
- Occupation
- big truck wrench/fixer of things
Bath-tub? Put the pipe down. On a serious note, a little dish soap diluted in a spray bottle is magical, bubbles never lie. If it leaks down when you lean on it you should be able to hear it leaking. Bath-tub? 
A tub would work nicely with a dieletric liquid made by 3M costing only about $1500/gallon. Next best thing would be water but that might damage the compresor if it runs before being completely re-dried. Before these I will try a soapy spray but I'm not optimistic.
The bottom pan is full of hay and maybe even manure, it's in a gaaawdawful shape! The air fittings are in shitty locations stuck in this caked goo, so I think I will have to first remove the compressor, the 2 shocks, the switch follow-up belt and somehow separate the leg scissors to do a proper sandblast and repaint job on it.
I'll do the soapy ritual next, maybe take pictures and be back later in the day. I thought I would get this out of the way while waiting for the clutch throwout bearings but it (too) is turning out to be a bigger job than anticipated
The bottom pan is full of hay and maybe even manure, it's in a gaaawdawful shape! The air fittings are in shitty locations stuck in this caked goo, so I think I will have to first remove the compressor, the 2 shocks, the switch follow-up belt and somehow separate the leg scissors to do a proper sandblast and repaint job on it.
I'll do the soapy ritual next, maybe take pictures and be back later in the day. I thought I would get this out of the way while waiting for the clutch throwout bearings but it (too) is turning out to be a bigger job than anticipated
terex herder
Senior Member
Check the exhaust side of valve first.
Some models have 4 air hoses, this one has only 3, 2 from the switch and one from the pump to the spring. Which is the exhaust side (I don't really understand what the switch does)?
The soapy ritual showed NOTHING though I could'n even get to the connection at the bottom of the spring. Nor could I get the pump hose off the spring, not even by heating it, so I cut it. But exercising the seat resulted in a sudden improvement though there was still very definite leakdown. So I went ahead with the stripping and am finishing the cleanup today. After this I'll try to test the 3 'air' components separately: the air-spring, the switch you mentiion, and the pump.
The soapy ritual showed NOTHING though I could'n even get to the connection at the bottom of the spring. Nor could I get the pump hose off the spring, not even by heating it, so I cut it. But exercising the seat resulted in a sudden improvement though there was still very definite leakdown. So I went ahead with the stripping and am finishing the cleanup today. After this I'll try to test the 3 'air' components separately: the air-spring, the switch you mentiion, and the pump.
Some of the Grammer seats that i’ve seen had a leaky air fitting where it screws into the bottom of the air spring. The fix was to remove the fitting and put sealer on the threads of the tiny fitting. The soapy water mist should find it
funwithfuel
Senior Member
Silly question, did you pump it rock hard full or just till the seat rose up? I've had guys pump em a little then go to sit only to have it collapse under their weight. I'd pump her up full, put a sandbag on the seat and start spraying soapy water. Good luck
I did it by ear so to speak and it seemed pumped up ok. Initially there was a serious leakdown (as in no load collapse) which later partly cured itself. There is a remote possibility that (because of little use?) there's nothing wrong with the air system but it's too late to stop now. Got all the parts cleaned up and painted. When I get around to testing I'll start with the pump and airspring with just plugs or a u-pipe in the switch ports. Otherwise I'll assemble everything loose and do all the tests as per the good book.
I did it by ear so to speak and it seemed pumped up ok. Initially there was a serious leakdown (as in no load collapse) which later partly cured itself. There is a remote possibility that (because of little use?) there's nothing wrong with the air system but it's too late to stop now. Got all the parts cleaned up and painted. When I get around to testing I'll start with the pump and airspring with just plugs or a u-pipe in the switch ports. Otherwise I'll assemble everything loose and do all the tests as per the good book.
There may be more but this one is a definite contributor. I noticed the nicks and condemned the compressor output tubing on that basis but then just blew into it and I was surprised that it was holding 'lung' air ...until I bent it a little. Didn't see any soap bubbles before as it was probably face down against the tray bottom that nicked it.
Other than the above frayed piping (for which FOR ONCE I just happened to have a yard of stock) there was only one issue that I had to devise a workaround for: one of the teleflex cable end traps in the switch was shot. Then I did the functional tests, all is like new, left to do is a bit of touchup, maybe staining the back rest JD green
Riveted a bent piece of aluminum
Riveted a bent piece of aluminum