View Full Version : 18.5 hp Briggs


cooter2506
09-03-2009, 06:54 PM
Engine model number is 31Q777. I changed the oil and after a few times mowing the yard it started to leak oil out of fuel pump. Replaced fuel pump, still does it. It also has oil comming from dipstick tube. While engine is running and you remove dipstick it sprays oil every where. We tore it down and adjusted valves, check breather tube, and breather reed. All look good. Any sugestions. This thing has only 191 hrs on it. About 20 hrs of that is leaving key on, LOL. Any help would be appreciated.

30yearTech
09-03-2009, 08:02 PM
Never remove the dipstick from a running engine! Make sure the engine is not overfull of oil. You may want to remove the oil breather and make sure the drain is not plugged. I would be suspicious of a blown head gasket as the cause of your problem.

cooter2506
09-03-2009, 08:05 PM
well we did have it apart and the head gasket looked fine. Also looked at the breather and reed. all clear and a vey small trace of oil in the breather valley.

30yearTech
09-03-2009, 08:15 PM
Well, then I would look for a leak into the crankcase that is preventing a vacuum from forming when the engine is running. A leaking sump gasket, top or bottom oil seal, dip stick seals etc...

Best of Luck.

cooter2506
09-03-2009, 08:31 PM
So if the dipstick tube is loose it could cause my problem. Because mine is loose so I will go out now and check the seal.

pyro_maniac69
09-03-2009, 08:35 PM
did you replace the head gaskets when you had the heads off?!?!?!?!?

cooter2506
09-03-2009, 08:50 PM
yes!!!

hd4ou
09-03-2009, 09:12 PM
If that dipstick is loose and not sealing it will lose vacuum and create problems.

cooter2506
09-04-2009, 01:35 PM
OK replaced seals on the dipstick and tube. Still does same thing. guess I will have to dig into her and find out where im missing vaccum. Any ideas