Hi everyone! Tired enough from crazy times here - freshly obtained a project to wrench on. A '94 Z28 Auto T-Top Camaro, with the body replaced by a '97 one. Not many people in my country who have a clue on this cars (if any), so, having high hopes on your community. Will be glad to maybe add to the common knowledge with the time.
More on the car: bacause of the mixture of a catfish body over the '94 "under the hood" and drivetrain I'm now messing around identification of what the previuous owned did put together. Definitely A/C parts mixed up (already in progress to get it right), but will need your help with identifying the year and type of the brakes in the car (there is a probability it's a system from 3,8 car, will post pics in a saparate post, appreciate help). The rest seems "healthy" so far, the girl is tail-happy, shifts good Has a cool leather interior with inflatable side-support seats, pleasant lighting upgrades (black and white all-LED side markers, turns, LED-lensed high and low beams etc). Needs care on cooling system. Had completely rotten inoperational radiator cap, temporarily replaced by a new one, but still behaves weirdly. The proper OEM cap is on the way, but by now the car pushes coolant into reservoire and is not sucking it back into radiator. I suspect the cap is the reason, can it be?. Hopefully not a blown head-gasket. It really raises coolant level in the reservoire and gets low level in the radiator every time i drive it even a little, like a one-way pump I have attampted to burp the air from the system with the raised front, even ran it with thermostat open, heater on, and fluid container with higher-levelled coolant amount put in place of radiator cap, but it still pumps coolant one way only into the catch-can. I suspect main sealing surface of the radiator cap is "weak contact", as the pressure spring is having enough tention as i put the cap on. Will soon see what a proper cap does to it.
Some pics attached
Alex

 

welcome to the forum. is this a converted v6 to v8? if it still does it with stock cap I would look at the hose and overflow tank pipe. if they leak it will suck air in when system cools.

 

merci! no, it was born as Z28, just the body was neglected to the scale it was simpler to replace the whole body. Thanks, the overflow pipe and tank I have checked (cleaned and pressure tested) as long the proper cap is being delivered. Big hopes the cap is the reason.
Another suspicion I have: possible wrong routing of coolant hoses during body transplantation. Have a workshop manual of 2948 pages, but can not find the proper scheme so far, need to find one and check with my reality.

 

by the way, do not do it like on the picture above, plastic bottle as a level-riser for the coolant. it gets hot and softens, almost melts, falls down

 

go here and download the factory service manual for your year,,,, years. 96 works for almost all of the 97 stuff. 98 covers any of the interior stuff, https://www.mediafire.com/?40mfgeoe4ctti

 

it's exactly the service manual I already have for '94. But the rest I did not, so thanks a lot! Weirdly enough, I could not find diagrams on coolant hoses in there. But, gratefully found a link here to a great site: 4th Gen LT1 F-Body Tech Aids-Drawings & Exploded Views which helped a ton, many thanks to the creator. I have everything connected as it should be for a '94 LT1, even oil cooler hoses are present. Will have to study now, why it is commonly bypassed.

 

I think it was 96 they switched to synthetic and did away with the oil cooler. has to be cap or maybe the radiator, check the area around where the cap goes see if its bent or damaged. your losing coolant somewhere, check for leak under the water pump

 

shbox is good,