Gas in Crankcase after Fuel Pump Change

[Snowdog]

So it seems there's gas getting into the crank case somehow.

I changed the fuel pump.

It sometimes needs a lot of cranking. Can flooding cause gas to slip past the rings?

Would adjustment of the Carter BBS be of any use?

Be gentle, I'm not a mechanic.

Thanks,

[jeffc57]

you may have bad fuel pump, the most common way fuel gets in the oil, ya I know you said its new but bad off the shelf is not uncommon, had one leak so bad that there was a extra quart in the crank, dipstick stank when pulled, inside of the engine sure was clean!!

[GMAN69]

The times I've seen this problem fuel tank was under pressure vented fuel tank and problem solved.

[Snowdog]

The times I've seen this problem fuel tank was under pressure vented fuel tank and problem solved.

How do I vent the tank? Remove the filler cap?

[712edf]

A properly working fuel cap will keep the tank from either pressurizing or getting vacuum.

I suspect the new fuel pump is bad. Gone through that myself last Fall. New Chinese made junk. The diaphragm is leaking, your gas is draining out of the line between the pump & carb into the crankcase. This explains the excess cranking.

Ethanol gas eats at rubber parts of fuel system too.

Yes gas can get past rings too, but that's less likely than the pump leaking.

Bucky

[Txas2step]

Just be aware that running the engine with excessive gas in the oil will wash out the bearings and cause serious damage. .Fuel pump most likely the culprit. Good luck.

[martincom]

I'm assuming this issue is with the '61 D100 listed in your signature. Unless a previous owner has REALLY jury rigged the fuel tank and it's associated plumbing, it wouldn't be a fuel tank venting issue.

In the later model sweptlines with the emission control vapor recovery, there would be a purge line connecting to an extra port on the crankcase breather.

[mopar]

I blame ethanol fuel for killing several fuel pumps and two 361 motors from 600 series trucks here.
Also had a $hithead know-it-all that failed to rebuild a carb correctly and the float would not close... when the behind the seat fuel tank was full and engine off, the cylinders, and then the crankcase would fill with fuel...
I now rebuild carbs myself.

Damn ethanol and the socialist government that legislated it... and $hithead know-it-alls.

{Excuse me. Hot day here making me more than a little cranky.}

[Snowdog]

I rebuilt the carb myself and was sure the float was working. First time, though.

Calling NAPA for a replacement pump. Thank God I like working on this '61. If nothing else, I'm learning tons.

[martincom]

A factory service manual will be the best investment you'll ever make in your truck. There are a couple of outfits producing very good re-prints at affordable prices.

https://www.faxonautoliterature.com/Sea ... &keywords=

http://www.autobooksbishko.com/search.c ... hop+Manual

https://www.factoryrepairmanuals.com/Do ... red&page=1

[GMAN69]

Check fuel line from pump to carb moving lines to replace pump line could be close to or against block or radiator hose picking up heat expanding fuel pushing it past needle and seat.