Reproduction Parts for 1916-1964 Chevrolet Passenger Cars & 1918-1987 Chevrolet & GMC Trucks
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I tested the compression on the engine today. It has no carb at this time so it is a cold compression test. I did the test dry and with 2 squirts of mystery oil in each cylinder. The numbers are as follows
#1 dry = 72 with oil = 80
#2 dry = 70 with oil = 75
#3 dry = 75 with oil = 80
#4 dry = 82 with oil = 80
#5 dry = 80 with oil = 90
#6 dry = 74 with oil = 80
I think the compression is pretty good for an old cold engine like this. Some seem a little unusual (see cylinder 4). The difference between 2 and 5 is good dry but with oil its a but outside acceptable. Overall I’ was happy with these numbers.
The issue I discovered is with the fuel pump. I just rebuilt it and it bench tested fine. It also pumped gas to the carb when it was on there. So I put a hose on the fuel tube where the carb mounts and ran it into a bucket to prevent gas from running out on the floor.
After all this compression testing the bucket was dry. I took the carb line off and cranked the engine with a rag under the fuel pump outlet. No gas. I took the fuel line off the inlet and vacuumed fuel from the tank to the pump so make sure the line was not clogged. That was fine.
I removed the filter as that looked dirty from the last time I got crud in the line. I removed the 2 valves from the top and cleaned them out. They looked fine. It wont even fill the glass at this point. But I can hear movement in the pump and I can feel intermittent puffs from the outlet.
I am really trying to not have to take this off again and rebuild it. Am I missing anything? I would think cranking the engine 4 times for each cylinder and repeating it for the oil phase would have put gas in the bucket. But then again…what do I know? This car really is a 1 step forward 2 steps back project.
Thanks for any help
Rich
Hi Rich
Is your glass bowl gasket cork or neoprene?
It doesn't take much of a leak at the bowl to really fowl things up.
Ole S Olson
Saskatoon, Sask, Canada
1946 DR 3/4 ton stake
1139 old site posts
It’s a new neoprene gasket. But you make a good point. When I took it off to get the filter out the gasket seems to have stretched out. It doesn’t fit right anymore. I had to get under the car and stuff it back in where it belongs. So that could be the issue. Maybe a wrinkle in the gasket. I have some nitrile here I could try to make a new one. I would likely need 2 as the nitrile is thinner than that neoprene gasket.
Thanks Ole!
I made a new gasket and the pump works again. I will order a new one as the one I made is kind of crude. It’s a little thin and not a perfect fit. But it fits enough for me to know it was the gasket.
@stovebolt-6 Go down to your local auto parts store. They will have cork gaskets in 3 or more sizes. Take one of your extra pumps to get the right size and buy 2 gaskets while you are there. This would be a good time to look through any extra pumps and choose a core that has a nice flat sealing area. It is pretty common for the pump body to be warped where the bowl seats. This is a result of over-tightening the bowl. There are methods for straightening them. Chip walked me through his procedure once but I have forgotten his method. Sorry for your trials and tribulations. We all go through this stuff every day. The sad part is that we think it is fun. Go figure.
Mike
Many Miles of Happy Motoring
3469 Posts on Old VCCA Chat
I have not used a neoprene or similar gasket for years. I use cork as it is far more tolerant of a glass bowl seat that is not flat. I have also tapered cork gaskets to adjust for the warp. Heated the castings to 400 deg F with a weight on the casting or glass bowl and then turning off the oven. Takes the warp from the parts. Caution: control the temperature accurately as 450 deg. F or higher may leave a puddle of silver colored metal.
How sweet the roar of a Chevy four
Participant on Chatter since 11/22/2001
19758 posts on the former Chatter site
New gasket and filter from TFS and the fuel pump works fine now.
Thanks for all the help guys!
@chip @stovebolt-6 @ole-olson There are at least 3 Fel Pro gaskets for glass sediment bowls. There might be more. The one that fits my '35/'36 pumps is #773. I also keep #4081 which is smaller and #5091 which is larger. I don't think I have ever failed to have one of them work on whatever old car-truck-tractor I am working on. The 773 is a bit small but can be used in the 1931-1949 oil filler cap.
Mike
Many Miles of Happy Motoring
3469 Posts on Old VCCA Chat
I may be embarrassed when I hear the answer...but I can't figure out what TFS stands for. (Then again, it took me a while to interpret FLAPS!)
Nick Gurin
Taos, New Mexico
1940 KC 1/2 Ton Pickup
The Filling Station 🙂
https://www.fillingstation.com/?srsltid=AfmBOopZq5vJVDMuVqHQKKho9O2WYymurbe8tEh4EzFStipVsWqfnRwh
Ole S Olson
Saskatoon, Sask, Canada
1946 DR 3/4 ton stake
1139 old site posts
Yup, feeling a bit thick! I have ordered several things from them, yet it didn't occur to me that TFS should be familiar.
Thanks!
Nick Gurin
Taos, New Mexico
1940 KC 1/2 Ton Pickup