I'm At A Loss!!!

jetsticks

Member
Joined
Mar 25, 2019
Threads
3
Messages
22
Ok. I think I've isolated the area where the leak is coming from. It's either coming from the brass looking circle on the fuel pump or the little slot holes that go all around the pump. It's a brand new fuel pump but could it be bad too?
 

Attachments

  • fuel pump.jpeg
    fuel pump.jpeg
    60.8 KB · Views: 11

StarTech

Lawn Royalty
Top Poster Of Month
Joined
Feb 19, 2020
Threads
93
Messages
11,589
Yes it is possible. I have a batch of Oregon pumps to fail short after install last year and Rotary pull all theirs last year as they were failing too. Even a new batch they got in last year as replacement for a batch got earlier failed their in house testing too. Left me having to buy OEM pumps. So far this year Oregon pumps seems to be okay.
 

MParr

Lawn Addict
Joined
Jul 2, 2021
Threads
8
Messages
1,717
Ok. I think I've isolated the area where the leak is coming from. It's either coming from the brass looking circle on the fuel pump or the little slot holes that go all around the pump. It's a brand new fuel pump but could it be bad too?
A brand new fuel pump can certainly be bad. OEM may cost a little more but it’s a better bet than many aftermarket pumps.
 

jetsticks

Member
Joined
Mar 25, 2019
Threads
3
Messages
22
That was an OEM but I will buy another and see what happens. I will post back here with the results. Thanks for everyone's help.
 

bertsmobile1

Lawn Royalty
Joined
Nov 29, 2014
Threads
65
Messages
24,995
Inside the fuel pump is just a diaphragm and 2 check valves
As the crankcase pressure is applied to the diaphragm is moves in & out
The brass disc is a filter because air has to be expelled to enable the diaphragm to go out .
If oil is coming from there then the usual culprit is a blown head gasket applying too much pressure to the pump diaphragm
oder fuel line is 2 or 3 tubes inside each other and it is easy to rupture the inner tube when removing or replacing the tubes
Petrol coming out of the brass filter = ruptured diaphragm .
.
 

jetsticks

Member
Joined
Mar 25, 2019
Threads
3
Messages
22
Inside the fuel pump is just a diaphragm and 2 check valves
As the crankcase pressure is applied to the diaphragm is moves in & out
The brass disc is a filter because air has to be expelled to enable the diaphragm to go out .
If oil is coming from there then the usual culprit is a blown head gasket applying too much pressure to the pump diaphragm
oder fuel line is 2 or 3 tubes inside each other and it is easy to rupture the inner tube when removing or replacing the tubes
Petrol coming out of the brass filter = ruptured diaphragm .
.
What if it’s not coming out of the brass filter but the little slots around the brass filter? Same thing? Blown gasket?
 

VRR.DYNDNS>BIZ

Well-Known Member
Joined
Jul 17, 2016
Threads
1
Messages
213
I have a Hustler Sport 48" ZTR with a 21 HP Briggs and Stratton engine. I noticed after mowing I had a bad oil leak coming from the oil pump to the carburetor. I inspected the line and saw no tears or holes so I thought it was the oil pump. I bought an OEM oil pump and installed it. The next time I mowed it was leaking again. I will say that when the mower is not engaged and just idling I don't see any leaks but after I engage the PTO oil starts to drip from the line that goes from the pump to the carb. I replaced the clamp on the pump with a hose clamp to make sure the old one wasn't too lose. Could the line have a pin hole or something? I did take it off and checked by putting an air hose in it and listening for any air. Any help would be appreciated.
It is a fuel pump. Oil emitted from that or lines means one of several issues. The breather controls crankcase vacuum. If it fails as a check valve, excessive loss of crankcase vacuum happens and flow increases with it able to carry a mist of oil out the line thru the pump and usually on to the air filter cavity as well. Another possible problem is a head gasket failure which then adds compression pressure to the crankcase over powering the breather. Another most common problem is oil over full or diluted by gas. If over full or very thin put a drop of oil on a piece of paper and wait 5 min to see if one consolidated ring is shown or gas creates a secondary ring which indicates gas dilution caused by a carb float problem. some find a flammability test of the oil defining as well. A lighter to the freshly dipped metal dipstick is ok for a badly diluted oil. The fact that oil appears under PTO load is a sign that all of the above are possible. Another quick test requires two people. remove the dip stick and seal the opening with your hand. Have someone start the cold engine and sense a vacuum or pressure. The only value of this test is proof of pressure or lack of vacuum, now you have to find the cause. Also make sure the oil is not hot for this test and not over filled. A compression test is not truly valuable to prove a bad head gasket, in stead a leak down test is needed. Short of that, prove all else not at fault and replace the head gasket. You can buy a manual for the engine. Enjoy.
 

WALDO1234

Forum Newbie
Joined
Oct 30, 2023
Threads
1
Messages
4
I have a Hustler Sport 48" ZTR with a 21 HP Briggs and Stratton engine. I noticed after mowing I had a bad oil leak coming from the oil pump to the carburetor. I inspected the line and saw no tears or holes so I thought it was the oil pump. I bought an OEM oil pump and installed it. The next time I mowed it was leaking again. I will say that when the mower is not engaged and just idling I don't see any leaks but after I engage the PTO oil starts to drip from the line that goes from the pump to the carb. I replaced the clamp on the pump with a hose clamp to make sure the old one wasn't too lose. Could the line have a pin hole or something? I did take it off and checked by putting an air hose in it and listening for any air. Any help would be appreciated.
Too much oil will cause it to blow out the breather
 
Top