Sudden Blow-by

The Cub Club -- Questions and answers to all of your Cub related issues.
Forum rules
Notice: For sale and wanted posts are not allowed in this forum. Please use our free classifieds or one of our site sponsors for your tractor and parts needs.
User avatar
Mac AR
Cub Star
Cub Star
Posts: 84
Joined: Mon Apr 22, 2019 2:33 pm
Zip Code: 72561
Tractors Owned: 51 Farmall Cub "The little 'un"
55 Farmall 300 "The Big 'Un"
60 IH 340U "The middle 'un"
Circle of Safety: Y

Sudden Blow-by

Postby Mac AR » Sun Oct 27, 2019 6:50 pm

I was working my '51 today, and its suddenly started smoking from the crankcase and the exhaust. If its under a good load it mostly goes away, but when coming up from idle it smokes pretty good. It looks like oil smoke rather than water, so I've ruled out a blown head gasket. Oil pressure is excellent, nearly pegs the gauge at full throttle, and is centered with the "I" on the gauge. I admit to being stumped, so if anyone could point me in a different direction I'd appreciate it.

Mac
"Go get me a crescent wrench... git the biggest SOB you can find 'cause I'm gonna use it fer a hammer ennyway" - Words of Wisdom from Dad.

Circle of Safety

Eugene
Team Cub Mentor
Team Cub Mentor
Posts: 19540
Joined: Fri Jul 02, 2004 9:52 pm
Zip Code: 65051
Circle of Safety: Y
Location: Mo. Linn

Re: Sudden Blow-by

Postby Eugene » Sun Oct 27, 2019 7:05 pm

Compression tests. Dry first then wet.

If you think it's burnt oil in the exhaust, then rings. Rings are about the only way oil gets in the combustion chamber. Minor amount of oil could be drawn past the valve stems but that is normally inconsequential.

Blow by, rings.
I have an excuse. CRS.

Waif
5+ Years
5+ Years
Posts: 1052
Joined: Thu Aug 25, 2016 1:29 pm
Zip Code: 49343
Tractors Owned: 48 Farmall Cub "Seen Yore Dobbin"
53 F-Cub W/Loader.
Circle of Safety: Y
Location: Michigan

Re: Sudden Blow-by

Postby Waif » Sun Oct 27, 2019 7:33 pm

Checked your oil level for excess fluid?
I've had the touch control leaking hydraulic fluid into crank case when the pump o-ring was bad . Not uncommon.
Gets messy though when oil is overfilled and thinned out!

User avatar
Mac AR
Cub Star
Cub Star
Posts: 84
Joined: Mon Apr 22, 2019 2:33 pm
Zip Code: 72561
Tractors Owned: 51 Farmall Cub "The little 'un"
55 Farmall 300 "The Big 'Un"
60 IH 340U "The middle 'un"
Circle of Safety: Y

Re: Sudden Blow-by

Postby Mac AR » Sun Oct 27, 2019 7:41 pm

That's what I was afraid of, Eugene. She was running fine last Sunday, and now today she's started smoking. I don't have a way to do a compression test, but I guess I'll have to get a gauge. I've not noticed a loss of power, if that's an indication of anything. Do you think I could've stuck a ring in a weeks time? Just thinking out loud. The engine was overhauled 2 or 3 years ago and wasn't used much until I bought it in the spring. It just seems oddly sudden, I guess. When I get a tester I'll let you guys know the results.

Waif, that's a good thought. It wasn't over filled best I can remember when I checked it before starting today. I'll check again in the morning and see though, that may be part of the issue.

Thanks again,

Mac

ETA: I went out to the shop and checked, it looks like the oil is just a fuzz over the line, and seems thin. I think I'll change it, just for the heck of it. Can't hurt and I'm sure its about due to be done.
"Go get me a crescent wrench... git the biggest SOB you can find 'cause I'm gonna use it fer a hammer ennyway" - Words of Wisdom from Dad.

Circle of Safety

User avatar
Don McCombs
Team Cub Mentor
Team Cub Mentor
Posts: 16135
Joined: Mon Feb 03, 2003 6:45 am
Zip Code: 21550
Tractors Owned: "1950 Something" Farmall Cub
1957 Farmall Cub w/FH
1977 International Cub w/FH
1978 International Cub
1948 Farmall Super A
Circle of Safety: Y
Location: MD, Deep Creek Lake

Re: Sudden Blow-by

Postby Don McCombs » Sun Oct 27, 2019 10:11 pm

Check the Touch Control level, too.
Don McCombs
MD, Deep Creek Lake

Image
Proud Member of Maryland Chapter 39
Circle of Safety

BigBill
10+ Years
10+ Years
Posts: 7388
Joined: Sat Jul 22, 2006 5:02 pm
Zip Code: 00000
Location: in northern usa

Re: Sudden Blow-by

Postby BigBill » Sun Oct 27, 2019 10:38 pm

Wash the crankcase breather in kerosene. The old cars with no pvc system we washed the crankcase breather in kerosene when changing the oil. Then add seafoam to the crankcase with new gas and to the gas tank then run it.
I'm technically misunderstood at times i guess its been this way my whole life so why should it change now.

outdoors4evr
10+ Years
10+ Years
Posts: 2639
Joined: Tue Jul 22, 2008 12:44 pm
Zip Code: 48370
Tractors Owned: 184
Location: Oxford, MI

Re: Sudden Blow-by

Postby outdoors4evr » Mon Oct 28, 2019 6:35 am

Rent a compression tester from Autozone. They refund your "rental" in full when you return the tool.
184 w/ Creeper & 3-Point
IH 3160a Mower
IH Model 15 Tiller
IH-54 Blade

User avatar
ricky racer
10+ Years
10+ Years
Posts: 5624
Joined: Wed Sep 12, 2007 8:40 pm
Zip Code: 49120
Circle of Safety: Y
Location: Niles / Buchanan, Michigan

Re: Sudden Blow-by

Postby ricky racer » Mon Oct 28, 2019 4:49 pm

outdoors4evr wrote:Rent a compression tester from Autozone. They refund your "rental" in full when you return the tool.

:Dito: :Dito:
1929 Farmall Regular
1935 John Deere B
1937 John Deere A
1941 John Deere H
1952 John Deere B
1953 Farmall Cub

User avatar
Mac AR
Cub Star
Cub Star
Posts: 84
Joined: Mon Apr 22, 2019 2:33 pm
Zip Code: 72561
Tractors Owned: 51 Farmall Cub "The little 'un"
55 Farmall 300 "The Big 'Un"
60 IH 340U "The middle 'un"
Circle of Safety: Y

Re: Sudden Blow-by

Postby Mac AR » Mon Oct 28, 2019 6:33 pm

Well folks, looks like I've figured out the cause of my smoke. When I checked the oil last night, I marked the stick with soapstone, and rechecked it. Up to the line, no higher. This evening, it was almost a 1/4 inch over the soapstone line. This leads me to believe my pump is leaking. I understand its just a fifty cent o-ring that goes bad. Any idea what size I need? Also, any pointers on replacing it? I'm certainly not afraid to tackle it myself, I'd just like some advice from y'all that have done it before. As always, thanks for your help.

Mac
"Go get me a crescent wrench... git the biggest SOB you can find 'cause I'm gonna use it fer a hammer ennyway" - Words of Wisdom from Dad.

Circle of Safety

Waif
5+ Years
5+ Years
Posts: 1052
Joined: Thu Aug 25, 2016 1:29 pm
Zip Code: 49343
Tractors Owned: 48 Farmall Cub "Seen Yore Dobbin"
53 F-Cub W/Loader.
Circle of Safety: Y
Location: Michigan

Re: Sudden Blow-by

Postby Waif » Mon Oct 28, 2019 6:58 pm

Pump shaft needs to be inspected for wear where o-ring rides. A groove defeats the seal.

Here's a mention of a different type of ring with double edges I believe. Could straddle the groove. Not saying you have a groove though. O-rings just plain fail too.
viewtopic.php?t=81109

You might consider replacing the rest of the seals , and a new gasket too..
Here's Rachel if you need morel support..
https://www.steinertractor.tv/v/touch-c ... /65479902/

Bob McCarty
Team Cub
Team Cub
Posts: 11101
Joined: Tue May 25, 2004 8:02 pm
Zip Code: 80501
Tractors Owned: Cubs, MH Pony, Shaw, Allis G, 1934 Silver King, JD LA and LI, Gibson D, David Bradley Tri-Trac
Circle of Safety: Y
Location: CO, Longmont

Re: Sudden Blow-by

Postby Bob McCarty » Mon Oct 28, 2019 7:20 pm

Pump shaft o-ring is a dash 112, buta-n. The pump can also be machined for a seal if it's deeply grooved. With the seal you can place the lip on a smooth area of the shaft.
"We don't need to think more,
we need to think differently."
-Albert Einstein

User avatar
Glen
10+ Years
10+ Years
Posts: 5340
Joined: Mon Mar 19, 2012 7:33 pm
Zip Code: 00000
Tractors Owned: 1956 Farmall Cub with Fast Hitch, F-11 plow, Disc, Cultivator, Cub-22 mower
Circle of Safety: Y
Location: Wa.

Re: Sudden Blow-by

Postby Glen » Mon Oct 28, 2019 9:25 pm

Hi,
Below is a listing from TM Tractor for the pump shaft o ring.

http://www.tmtractor.com/new/hy/396fp.htm

Below is a listing for the pump rebuild kit, it has several parts, among them are, a gasket for the top end of the Touch Control tubes, and o rings for the lower end of the tubes, and a gasket for where the pump bolts to the engine.
There is an o ring for where the 2 halves of the pump join together.

http://www.tmtractor.com/new/hy/288fp.htm

The pump is held on the engine by 2 of the 4 bolts in it. Looking forward from the rear of the pump, the upper left, and the lower right bolts hold the pump on the engine, they go through the pump.
Don't remove the other 2 bolts until you get the pump to a bench, it can fall apart.
You can loosen them though, while the pump is bolted to the engine.

The pump drive gear should have a lock washer that bends over one flat of the nut, to keep the nut and gear from falling off.
You have to bend the washer away from the nut to remove the nut.
The washer has to have a tab that sticks into the keyway of the shaft, to keep the washer from turning. Sometimes the tab breaks off, then it needs a new lock washer.
TM Tractor has a new lock washer.

Wash the outside of the pump before taking it apart, if it is dirty. Be careful to keep all dirt out of the two holes in the end of the pump.
Work on the pump in a clean area.
Use plenty of new Hy-Tran fluid when putting the pump together.

Below is a pic from TM Tractor of the lock washer. :)
Attachments
Cub T C pump.jpg

Gary Dotson
Team Cub Mentor
Team Cub Mentor
Posts: 4851
Joined: Thu Aug 03, 2006 6:20 am
Zip Code: 43358
Tractors Owned: 48 Cub Diesel (Cubota)
53 Cockshutt 20 restored (Shooter)
52 Cockshutt 20 unrestored
47 Leader "B" (Herckie)
49 Leader "D" (Princess)
49 Leader "D" very rough
48 Leader "D" unrestored
Kubota B6200E
Kubota B6200HST
Kubota B8200HST-D
Circle of Safety: Y
Location: OH West Mansfield

Re: Sudden Blow-by

Postby Gary Dotson » Tue Oct 29, 2019 7:33 am

You might be jumping to a premature conclusion. When a Cub engine is shut down and the oil checked, it will be at a given level on the dip stick, as it sits, the oil will drain from the filter housing to the oil pan, raising the level on the stick. Did you check the fluid level in the touch control?? If it's not low your pump is not leaking.

User avatar
Don B.
5+ Years
5+ Years
Posts: 366
Joined: Thu Jul 02, 2015 12:02 pm
Zip Code: 25314
Tractors Owned: 1948 Cub (looks pretty)
1951 Cub (does the work)
1952 Cub (sold)
Circle of Safety: Y
Location: Charleston, WV

Re: Sudden Blow-by

Postby Don B. » Tue Oct 29, 2019 8:20 am

So, will a bad hydraulic pump seal cause a sudden blow by condition?
From what I see in this thread, it sounds like it can?
Considering it was sudden, I was leaning toward a broken ring or some other such ring problem, but maybe not?
Circle of Safety

Waif
5+ Years
5+ Years
Posts: 1052
Joined: Thu Aug 25, 2016 1:29 pm
Zip Code: 49343
Tractors Owned: 48 Farmall Cub "Seen Yore Dobbin"
53 F-Cub W/Loader.
Circle of Safety: Y
Location: Michigan

Re: Sudden Blow-by

Postby Waif » Tue Oct 29, 2019 9:14 am

When my pump o-ring seal went from mildly bad to bad and over filling engine crankcase , there was oil droplets falling on the hood from exhaust.
With the attendant "smoker" syndrome.

Did not go farther in checking things out beyond than having o-ring replaced ,oil changed.

Was thinned oil getting past rings? It was getting in the fireboxes from somewhere.....

Not being over run with hungry machinists , I had the pump replaced with one in better condition when the original started leaking again.


  • Similar Topics
    Replies
    Views
    Last post

Return to “Farmall Cub”

Who is online

Users browsing this forum: Flemmingth and 2 guests