Allis B overheating
Printed From: Unofficial Allis
Category: Allis Chalmers
Forum Name: Farm Equipment
Forum Description: everything about Allis-Chalmers farm equipment
URL: https://www.allischalmers.com/forum/forum_posts.asp?TID=211085
Printed Date: 02 Oct 2026 at 7:57am
Software Version: Web Wiz Forums 11.10 - http://www.webwizforums.com
Topic: Allis B overheating
Posted By: john2189
Subject: Allis B overheating
Date Posted: 14 May 2026 at 6:53am
|
I have asked before but don’t know how to find old posts. My B after about 20 minutes of mowing with a woods l59 will lock up. After about 10 minutes, it will restart. I assume the pistons are expanding and making it lock up. Any way, I asked the best way to flush the system but couldn’t find my old post, so I am asking again. John ------------- '41 Allis B '49 Farmall Cub |
Replies:
Posted By: steve(ill)
Date Posted: 14 May 2026 at 7:57am
|
i take the lower radiator hose off... stick a garden hose in the top of the radiator and turn it on...flush out everything you can with engine off.... On a real bad engine i pull the thermostate out ( also good inspection)..reinstall the housing and hose, and stick the garden hose into the top of radiator..... Let the water fill up the bock and overflow and start engine to pump water around inside.... you can pinch the lower hose 50% to guarantee overflow from the top, if needed.
------------- Like them all, but love the "B"s. |
Posted By: john2189
Date Posted: 14 May 2026 at 8:45am
|
Thanks Steve. ------------- '41 Allis B '49 Farmall Cub |
Posted By: PaulB
Date Posted: 14 May 2026 at 8:55am
|
Sometimes you can dislodge dirt/scale easier by forcing water backwards through the radiator (garden hose into the bottom) than pouring water in the top. If you can also ad an air jet along with the hose that will loosen more dirt/scale. ------------- If it was fun to pull in LOW gear, I could have a John Deere. Real pullers don't have speed limits. If you can't make it GO... make it SHINY |
Posted By: steve(ill)
Date Posted: 14 May 2026 at 9:36am
|
mud, crud, rust, seems to settle inside the block around the piston liners.. It is amazing how much buildup you can get in that area... and yes, it does restrict the cooling on the lower half of the liner.. ------------- Like them all, but love the "B"s. |
Posted By: john2189
Date Posted: 14 May 2026 at 2:27pm
|
Would it help to remove water pump and thermostat housing ? ------------- '41 Allis B '49 Farmall Cub |
Posted By: john2189
Date Posted: 14 May 2026 at 3:10pm
|
Ok took thermostat housing off and the big spring was broken into 3 pieces and what looked to be a rubber seal? The flapper is loose, I can move it with a screw driver. Now to run water where the water pump bolts to to see what comes out. ------------- '41 Allis B '49 Farmall Cub |
Posted By: steve(ill)
Date Posted: 14 May 2026 at 3:47pm
|
flush it up, down , in , out ... then fill and run 10 iminutes , drain and do it again... if its coming out dirty or orange, its caked in around the liners... a failed thermostat can block the flow also... might try running without and see how it does.. ------------- Like them all, but love the "B"s. |
Posted By: john2189
Date Posted: 14 May 2026 at 5:26pm
|
Im planning on not putting a thermostat in. I will run water in water pump hole and thermostat hole several times. Then reinstall the thermostat housing, water pump and radiator, then fill with water and start it up and flush some more. ------------- '41 Allis B '49 Farmall Cub |
Posted By: Les Kerf
Date Posted: 14 May 2026 at 7:38pm
If there is no danger of freezing I would put in a quart of white vinegar, top off with water, warm it up fully, and let it sit overnight before draining. Maybe repeat several times. Best wishes
 |
john2189 wrote:Posted By: WF owner
Date Posted: 15 May 2026 at 7:03am
| Don't overlook cleaning the outside of the radiator. Mud, oil and grease can build up inside the fins and block air flow through the radiator. |
Posted By: john2189
Date Posted: 15 May 2026 at 8:43am
|
Ok flushed block. Didn’t get much crud out of it, just the dirty anti freeze. Same with the radiator. I will next put it back together, put a Qt of white vinegar in and fill it up and run it till it warms up, drain and another qt of vinegar and do it again. Since I didn’t get any crud out of it, I wonder if it was just the thermostat causing the problem. ------------- '41 Allis B '49 Farmall Cub |
Posted By: steve(ill)
Date Posted: 15 May 2026 at 9:27am
|
yes... thats a good possibility that the failed thermostat was the problem... Blow/ wash out the outside of the radiator as WF mentioned... ------------- Like them all, but love the "B"s. |
Posted By: HudCo
Date Posted: 15 May 2026 at 9:28am
| have you checked for compresssion in the radiator |
Posted By: john2189
Date Posted: 15 May 2026 at 1:27pm
You mean like a blown head gasket? No I don’t see any bubbles while it’s idling ------------- '41 Allis B '49 Farmall Cub |
Posted By: john2189
Date Posted: 15 May 2026 at 1:32pm
|
I got it back together and it ran mowing grass for about 45 minutes. Seamed to run ok. Of course there was a couple small leaks, but they stopped leaking after it warmed up. So I will flush again and run it. Thanks for all your help. ------------- '41 Allis B '49 Farmall Cub |
Posted By: john2189
Date Posted: 25 May 2026 at 11:29am
|
Ok mowed about 1-1/2 hours, ran great, but when I shut it off, it started leaking water out the weep hole of the water pump. Any recommendations to where to buy one? The jungle site has one for 77$. ------------- '41 Allis B '49 Farmall Cub |
Posted By: SteveM C/IL
Date Posted: 25 May 2026 at 12:52pm
| A&I had one for my WD a few yrs ago.... |
Posted By: steve(ill)
Date Posted: 25 May 2026 at 12:59pm
|
$70- 90 seems to be the going price.. If Amazon has free shipping, that would be a good buy. ------------- Like them all, but love the "B"s. |
Posted By: john2189
Date Posted: 25 May 2026 at 2:52pm
|
I assume they are all made in China. Not that is bad. ------------- '41 Allis B '49 Farmall Cub |
Posted By: steve(ill)
Date Posted: 25 May 2026 at 3:40pm
|
yea.... i would BET on that.. ------------- Like them all, but love the "B"s. |
Posted By: john2189
Date Posted: 05 Jun 2026 at 8:49pm
|
Mowed lawn today with the B. It stopped running twice. After a couple of minutes it Turned over really slow then started and ran great for about 1/2 hour then did it again. Let it sit for two or three minutes and it starts right up. Temperature gauge stays in the white , almost into the green. Does not seem to be over heated, no steaming, no smell, not boiling over. When I flushed the cooling system it didn’t seem to be all that dirty. Could something else be getting tight enough to make the engine lock up? Distributor, distributor drive, 10si alt ? just put a new water pump on. Can’t turn with crank when it happens. 🤷🏻♂️ ------------- '41 Allis B '49 Farmall Cub |
Posted By: steve(ill)
Date Posted: 05 Jun 2026 at 9:03pm
|
Can’t turn with crank when it happens. ------------- Like them all, but love the "B"s. |
Posted By: john2189
Date Posted: 05 Jun 2026 at 10:16pm
|
I’m still thinking pistons and liners is swelling. But wouldn’t the liner o rings start to leak? No water in oil pan. ------------- '41 Allis B '49 Farmall Cub |
Posted By: HudCo
Date Posted: 05 Jun 2026 at 10:42pm
| is the starter staying in |
Posted By: john2189
Date Posted: 06 Jun 2026 at 6:18am
No, it is running when it shuts off. ------------- '41 Allis B '49 Farmall Cub |
Posted By: john2189
Date Posted: 06 Jun 2026 at 6:25am
|
Could the timing cause this? ------------- '41 Allis B '49 Farmall Cub |
Posted By: WF owner
Date Posted: 06 Jun 2026 at 7:06am
| How were the sleeves installed? What was used to lubricate the O rings on the outside of the sleeves during installation? |
Posted By: john2189
Date Posted: 06 Jun 2026 at 7:38am
I don’t know the history of this tractor. I bought a few years ago. ------------- '41 Allis B '49 Farmall Cub |
Posted By: SteveM C/IL
Date Posted: 06 Jun 2026 at 12:21pm
| You could pull pan and look at liners lower part. If it's seizing pistons you should have nice score marks... |
Posted By: HudCo
Date Posted: 06 Jun 2026 at 12:35pm
| sure starter drive isnt stuck in the flywheel while the engine is running and killing the engine when the starter locks up and staying in the flywheel until it cools. drive can stay stuck in even with out electrical power . can you push in the clutch and turn everything else in every gear and with pto on |
Posted By: john2189
Date Posted: 06 Jun 2026 at 12:56pm
Never thought of that. Hmm one of those little cameras for the phone down the spark plug hole should be the same. Now I have a reason to buy one. 🙂 ------------- '41 Allis B '49 Farmall Cub |
Posted By: john2189
Date Posted: 06 Jun 2026 at 1:00pm
If starter was stuck, wouldn’t it make noise? ------------- '41 Allis B '49 Farmall Cub |
Posted By: wjohn
Date Posted: 06 Jun 2026 at 2:23pm
It's silly not to buy one for what they cost these days. Very handy. ------------- 1939 B, 1940 B, 1941 WC, 1951 WD, 1952 CA, 1956 WD-45 |
Posted By: HudCo
Date Posted: 06 Jun 2026 at 8:17pm
| looking down the bore wont show the bottom half of the sleave where the o ring area isif its beat up above the piston at bottom dead center then its probley an oil burner or soon will be need to look up from the pan side with five lbs on the coolant system at tdc each cylinder . is oil making it to the rocker shaft when running |
Posted By: john2189
Date Posted: 06 Jun 2026 at 8:29pm
It doesn’t burn oil. Ill look down the oil cap when it is running to see if its getting oil. ------------- '41 Allis B '49 Farmall Cub |
Posted By: Les Kerf
Date Posted: 06 Jun 2026 at 8:54pm
On the several occasions I have encountered this (different engines) it has always made quite a noticeable racket.
|
Posted By: SWPennTom
Date Posted: 07 Jun 2026 at 6:42am
| I'm having the same issue with my '48 C; it runs fine for a little while then starts to lose power and stops. I just had an engine overhaul, top to bottom due to an engine knock, burning oil and excessive oil leaks from the front & real seals If I let the tractor sit for 20-30 minutes it starts right up, but a hour or so into running, it will stall. The symptoms point to a failing mag coil. When the faulty coil gets hot, the spark gets weaker and weaker. I'm reading on tractor forums that mag coil quality is somewhat questionable. Ordered a new coil ( from Brillman.com ) for the FMJ 4B3, which is a rebuilt unit I got a few years ago, so I don't have results of the replacement to report. I'll follow up. |
Posted By: john2189
Date Posted: 07 Jun 2026 at 6:56am
Thanks, I have a distributer on mine. My engine locks up tight when it stalls. ------------- '41 Allis B '49 Farmall Cub |
Posted By: john2189
Date Posted: 07 Jun 2026 at 6:59am
|
If i pull the head, would I be able to see down the water passage if the liners are full of crap, causing it to overheat? ------------- '41 Allis B '49 Farmall Cub |
Posted By: Steve in NJ
Date Posted: 08 Jun 2026 at 9:09pm
|
When I restored my B about 20 years ago, that engine had so much muck around all the cylinders, I couldn't believe what I was seeing. It took me a couple hours just cleaning up all the muck inside of the block. The engine was stuck when I got the Tractor, so I never had it running to where it might have been overheating, but it musta' run pretty hot for the previous owner. I did do all new sleeves and pistons when I rebuilt the engine. Once I put the Tractor in service, it never ran hot. Even today in the hot weather, still stays right in the same area. Always was just below the green area on the gauge... Steve@B&B ------------- 39'RC, 43'WC, 48'B, 49'G, 50'WF, 65 Big 10, 67'B-110, 75'716H, 2-620's, & a Motorhead wife |
Posted By: WF owner
Date Posted: 09 Jun 2026 at 5:00am
| You mentioned a while back that you were getting coolant out the weep hole in the water pump. Did you replace the water pump? |
Posted By: john2189
Date Posted: 09 Jun 2026 at 6:14am
Yes I replaced the water pump. ------------- '41 Allis B '49 Farmall Cub |