bamaboybv Posted March 1, 2013 Report Share Posted March 1, 2013 Picked up a beater shee for a few bucks. Went to check compression but gauge wont hold psi. When I kick it jumps to 30, then immediately falls. I kick again ... Same thing. Is it a bad compression gauge ( cheap gauge ) or could it be motor problems. Thanks for your time. I did the thumb test and both cylinders feel ok but thumb test doesn't tell much. My hand is not on the pressure release either. Quote Link to comment Share on other sites More sharing options...
bamaboybv Posted March 1, 2013 Author Report Share Posted March 1, 2013 Oh yes I held the throttle open, and followed the Clymer. Thanks again fellers Quote Link to comment Share on other sites More sharing options...
trickedcarbine Posted March 1, 2013 Report Share Posted March 1, 2013 Find another gauge known to work, then check it again. If it still does that, it is time for a rebuild. Quote Link to comment Share on other sites More sharing options...
blowit Posted March 1, 2013 Report Share Posted March 1, 2013 The pressure on the gauge should not drop regardless. There should be a shrader valve in the very tip of the threaded insert. If they leak, the pressure will fall. Pressure should hold indefinitely. Quote Link to comment Share on other sites More sharing options...
bansheesandrider Posted March 1, 2013 Report Share Posted March 1, 2013 The pressure on the gauge should not drop regardless. There should be a shrader valve in the very tip of the threaded insert. If they leak, the pressure will fall. Pressure should hold indefinitely. X2 Quote Link to comment Share on other sites More sharing options...
bamaboybv Posted March 1, 2013 Author Report Share Posted March 1, 2013 Blow it was right.... I forgot that I was using air at the shop to change the springs for a cam swap on my lt1 impala SS. I took the Schrader valve out. I got it back in now I will check it after I build this 4t80e at work. Working on trannys has made me less sharp with my engine diagnostics. Thanks guys this was a duh moment. Thanks again for all the help. Y'all have a good weekend Quote Link to comment Share on other sites More sharing options...
sheerider11 Posted March 1, 2013 Report Share Posted March 1, 2013 Blow it was right.... I forgot that I was using air at the shop to change the springs for a cam swap on my lt1 impala SS. I took the Schrader valve out. I got it back in now I will check it after I build this 4t80e at work. Working on trannys has made me less sharp with my engine diagnostics. Thanks guys this was a duh moment. Thanks again for all the help. Y'all have a good weekend fishing for compliments? Quote Link to comment Share on other sites More sharing options...
Nieskes Posted March 1, 2013 Report Share Posted March 1, 2013 I think he feels extra cool today. Quote Link to comment Share on other sites More sharing options...
Nightmare Posted March 1, 2013 Report Share Posted March 1, 2013 Its a 4l80E by the way. Sent from my SGH-T679 using Tapatalk 2 Quote Link to comment Share on other sites More sharing options...
bamaboybv Posted March 1, 2013 Author Report Share Posted March 1, 2013 Nightmare350 no it's not I'm on break and I'm standing right beside it It's a 4t80e it's a fwd tranny outta Cadillac north stars the tranny is L shaped We HARDLY ever build 4l80es and Allison's they just don't break 4l80 might be what you're referring to they are in trucks cargo vans and guys shove em in street rods in place if the weaker 4l60e thanks. Allison's are basically a dump truck tranny but don't go around saying you're building 4l80e's cause I've only built 1 EVER. They are heavy duty but they can and do break occasionally thanks bros Quote Link to comment Share on other sites More sharing options...
Nightmare Posted March 1, 2013 Report Share Posted March 1, 2013 Nightmare350 no it's not I'm on break and I'm standing right beside it It's a 4t80e it's a fwd tranny outta Cadillac north stars the tranny is L shaped We HARDLY ever build 4l80es and Allison's they just don't break 4l80 might be what you're referring to they are in trucks cargo vans and guys shove em in street rods in place if the weaker 4l60e thanks. Allison's are basically a dump truck tranny but don't go around saying you're building 4l80e's cause I've only built 1 EVER. They are heavy duty but they can and do break occasionally thanks bros I see, my bad dude. Sent from my SGH-T679 using Tapatalk 2 Quote Link to comment Share on other sites More sharing options...
So Cal Suspension Posted March 1, 2013 Report Share Posted March 1, 2013 You're putting a front wheel drive tranny into a rear wheel drive car? Quote Link to comment Share on other sites More sharing options...
bamaboybv Posted March 1, 2013 Author Report Share Posted March 1, 2013 Don't worry bout it dude I do not know everything but what I do know is to replace my schrader after doing a valve spring/seal replacement @sheerider I'm a dad lol so I never look for compliments lol ya know how it is use daddy and toss him to the side well breaks almost over bout to go hit it for 2 more hours then .... WEEKEND Quote Link to comment Share on other sites More sharing options...
bamaboybv Posted March 1, 2013 Author Report Share Posted March 1, 2013 No Matt he thought I meant I was building a 4l 80 but I was building a caddy trans simple mistake Quote Link to comment Share on other sites More sharing options...
trickedcarbine Posted March 1, 2013 Report Share Posted March 1, 2013 Its a 4l80E by the way. Sent from my SGH-T679 using Tapatalk 2 By the way, A 4t80e is the heavier duty FWD tranny. So, just realize that because you Havnt heard of it doesn't mean it's not legit. And Bama, 4L80's do go bad. I used to work in a transmission core warehouse and we deal with a lot of the GM surplus and a few big auto salvage yards accross the nation. There have been days where I unloaded 2 53 foot trailers of nothing but 4L80's. All in those stupid ass coffins! They are actually worth a lot of cash for he cores because not many parts are available. We bought cores at the door and paid $500 cash for em IF I dropped the pan and didn't see a fucking grenade! Quote Link to comment Share on other sites More sharing options...
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