(800) 853-2651
SHOP NOW

oil pressure

R

rockepg

Member
Just finished rebuilding my z145 and got it fired up. Finally.... When i first started it the oil pressure was about 30. I ran it long enough to get it up to temp twice. First to re-torque the head bolts and once to adjust the rockers. The pressure at idle is now sitting at 10 and making some not so happy noises. The rockers barely get any oil, like only a couple drops. Did rebuild the pump and packed with grease for initial startup. I know the rear main bearing is installed correctly with the large holes towards the block per manual.

What am i missing here?
 
What noises is it making?

Low oil pressure at idle means clearance issues to me, or noises could mean you spun a bearing.
 
Not hammering or anything like spun bearing. Normally i would say clearance issue too. Bearings all plasti-gauged to .0015 so that shouldn't be an issue. Block and head were tanked and brushes run through all the journals so there is no clogs. Almost like the relief valve on the pump sticks open when it warms up or something.
Noises are light like the valves which makes sense with little to no oil up there.
Started it up this morning and i have 30 psi again but have not let it warm up to see what happens.
 
The oil pressure should be 20 - 30 psi @ 1500 rpm (engine at operating temperature). The relief spring when removed from the oil pump it should be 2" long. It should take 8 1/2 lbs of pressure to compress the spring to 1 3/8" long.
3098.jpg
 
Yep i rebuilt the pump per the manual. The spring was the correct length and had the correct amount of pull at the specified compressed length. Actually the pull was 8.6-8.7 pounds at the 1 3/8 length which is good. There was no shims in there originally. Kind of wondering if i need to add one or two. I did rebuild the pump so it has new spring, plunger, both gears and bushings as well as drive gear. .006 was the lash at the pump gear to crank.
Not sure if it matters or not but i did also convert to a spin on filter..
 
When you said 'spun bearing'... you better dig into it again now. The first Z129 i did gave me a time lining up the rear main passages- I enlarged it with a die grinder... and polished the insert with dental instruments... no other 'cheap' choices there. cause that is where the oil to the top end and gauge- come from- the passage on the top cap of the rear main- or am i wrong once again? But if she sounds spun, getting no more oil on top, low pressure... you better take that insert off right now. I always play my hunches first.
 
No sounds like spun bearings or knocks. With the motor cold it gets 30 pounds at idle. When it gets up to temp that drops down to 8-10 pounds and things just sound "heavy" if that makes any sense. I'll warm it up again and see if the pressure still drops off and if it does i guess only option is to drop the pan and start poking around.
What is used for pressure valve shims? Assuming i'll have to improvise something. This is of course assuming everything is actually ok.
 
Ok figured a washer of some kind, just wasn't sure on the thickness. Thanks for the info. Wife is out of town for 10 days starting monday so i'll have the place to myself and will dig back into it and see what happened.
Couple other things i want to try first like blowing air down from the rocker shaft oil hole and see if i can hear air escaping somewhere. Bleed the air out of the oil pressure gauge. Things like that just to make sure i am not chasing something dumb.
 
My z134 has about 45 psi cold, and around 25 psi at 1500 rpm. I didn't like the original bypass oil filter, so I made it full flow filter system (all the oil goes through the oil filter before it goes to the bearings) with a external adjustable bypass valve. I can either change the bypass spring, or add a shim in a minute, or two. https://www.youtube.com/watch?v=8rvrhf8Nfso
 
Ya have seen your setup before, that is nice. Was thinking next machine i get i might do something similar. Would like to find a diesel for next one but we'll see.
 
I got a 135 diesel to replace that one, if you ever get a diesel you will be throwing rocks at the old gasser. The diesel will go through things that would lug the gasser down so hard that it will would just about kill the engine on the gasser if you didn't push the clutch in to let the gasser catch it breath.
 
Ok got the pan dropped. Pulled all the bearings,both halves, including that pita rear one. All were good and just starting to get shiny. Blew air down the rocker shaft feed hole and can feel the air coming out around the rear cam journal so the head gasket is on correct and no blockages. I have a .040 and a .060 washer the right diameter for the relief valve. Which would you suggest using?
 
You may decide it's of good value to check the bearing clearances with Plastigue, as you are at a point where it cost you only a few cents for the plastiqaue:
If you have to take the pan off twice......^*&^%$&*(@*&*

Bob...
 
I was thinking the same. Will pull the pump back apart too and just make sure i didn't miss something in there. Not finding any silver bullets so far..
 
The one good thing about the Z134 engine is that the oil pan can be dropped without having to completely split the front axle support. The Perkins uses the oil pan only to hold the front axle support in place, but the Perkins is a way better engine.
 
Ok this appears to be resolved. Parts depot had a nos, new old stock, pump body collecting dust on the shelf. That combined with new build kit seems to have done the trick. 32psi cold on idle and 30psi up at operating temp on idle. Rockers have a very slow drip coming out from around the bushings so think it's good. Clearances were good but appears at some point the cover side of the body might have been milled a hair as the gears stuck up from the body about .005. That and the thicker gasket the original kit came with i think just put to much room in there.
 
You must log in or register to reply here.

Similar threads

G
TO35 low oil pressure when hot
Replies
9
Views
1K
GaryTO35
G
J
WD45 Diesel Oil Pressure
Replies
10
Views
576
DrAllis
D
L
Super A Oil Pressure
2 3
Replies
48
Views
2K
kshansen
K
J
John Deere B oil pressure
Replies
3
Views
344
buickanddeere
B
C
Head Re-Torque Technique (3T84HLE)
Replies
0
Views
723
winston-HT
W
Tractor Parts Tractor Manuals

We sell tractor parts! We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today.

Copyright © 1997-2024 Yesterday's Tractor Co.

All Rights Reserved. Reproduction of any part of this website, including design and content, without written permission is strictly prohibited. Trade Marks and Trade Names contained and used in this Website are those of others, and are used in this Website in a descriptive sense to refer to the products of others. Use of this Web site constitutes acceptance of our User Agreement and Privacy Policy TRADEMARK DISCLAIMER: Tradenames and Trademarks referred to within Yesterday's Tractor Co. products and within the Yesterday's Tractor Co. websites are the property of their respective trademark holders. None of these trademark holders are affiliated with Yesterday's Tractor Co., our products, or our website nor are we sponsored by them. John Deere and its logos are the registered trademarks of the John Deere Corporation. Agco, Agco Allis, White, Massey Ferguson and their logos are the registered trademarks of AGCO Corporation. Case, Case-IH, Farmall, International Harvester, New Holland and their logos are registered trademarks of CNH Global N.V.

Yesterday's Tractors - Antique Tractor Headquarters
Website Accessibility Policy

Back
Top