B7100 Oil Pressure at normal operating temp

[Jimc3165]

If you have one of the older B7100 or B5100 or maybe any of the 80's models, I'm looking to get an idea what your oil pressure is at full throttle and then at idle after you reach normal operating temp. I installed a pressure gauge on mine and a new sending unit and have yet to see the idiot light at an idle but my pressure falls down to 20lbs at idle and around 40 at full throttle, is this what you are seeing? Again just trying to get an idea if what I'm seeing is normal for a 35 year old tractor.

 

[100 td]

Sounds good to me, IIRC the lamp comes on at 7 pounds (but that's from memory so could be wrong), the specs are in a thread here somewhere or probably in the service manual.
http://www.kubotabooks.com/AutoIndex/index.php?dir=Tractor%20Owners%20Manuals/

 

[85Hokie]

Jim,

92 model B7100 ......

start-up - close to 60 psi (maybe 57 ish)

after running hard for a while (30 minutes) still up there at 45 ish at 90% WOT

allowing to drop to idle ......17-20 psi at the slowest idle. Any increase in speed...it moves up quickly to 40.

15w-40 Rotella T6

 

[Jimc3165]

Jim,

92 model B7100 ......

start-up - close to 60 psi (maybe 57 ish)

after running hard for a while (30 minutes) still up there at 45 ish at 90% WOT

allowing to drop to idle ......17-20 psi at the slowest idle. Any increase in speed...it moves up quickly to 40.

15w-40 Rotella T6

Thanks
This is what I am seeing right now but am a little concerned still. I haven't had a chance to run it hard yet for an hour or more. I took the gear case cover off thinking I had the cam plug problem but it was there. So I replaced the sender and used your installation instructions to install the pressure gauge. Just hoping it was the sending unitcausing the light to come on.

 

[D2Cat]

Jim, what 100td mentioned is correct. The light is suppose to come on showing low oil pressure at 7#. It's in the WSM. I don't think you need to be concerned, just use your tractor and she'll probably go another 20 years...at least!!

 

[Jimc3165]

Thanks D2, I used it for about an hour today at WOT mowing with the MMM and the light still didn't come on so I guess it was a bad sending unit. The Oil pressure did drop however to about 16lbs at idle.

 

[85Hokie]

"drops to about 16lbs at idle"

That's perrrrrfect!