7020 heater control
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=146839
Printed Date: 21 Sep 2025 at 5:23pm
Software Version: Web Wiz Forums 11.10 - http://www.webwizforums.com
Topic: 7020 heater control
Posted By: Blustery Knoll Farm
Subject: 7020 heater control
Date Posted: 24 Jan 2018 at 9:20pm
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My 7020 blows lukewarm air out of the heater. And the temperature control knob is stuck. I pulled the cab roof off, and it looks like there's supposed to be a cable hooked up to the little gear wheel. No sign of it though. Where's the actual location of the control valve? It seems like it is likely stuck part way open. |
Replies:
Posted By: Orange Blood
Date Posted: 24 Jan 2018 at 10:18pm
On the right hand side (seated) of the heater core, there should be a 90 deg. fitting with a metal plate on the end of it. there should be a little lever that should have a cable attached to it, that would run over to the heater knob. Lot of "shoulds"  There may also be a valve up around the engine somewhere. The heater valve that should be hooked up, was notorious for not shutting off completely, thus making the AC nearly ineffective, so check for another valve in the lines, (farmer added)------------- Still in use: HD7 WC C CA WD 2-WD45 WD45LP WD45D D14 3-D17 D17LP 2-D19D D19LP 190XTD 190XTLP 720 D21 220 7020 7030 7040 7045 3-7060 Projects: 3-U UC 2-G 2-B 2-C CA 7-WC RC WDLP WF D14 D21 210 7045 N7 |
Posted By: Blustery Knoll Farm
Date Posted: 24 Jan 2018 at 11:15pm
| I just see two rubber hoses connected to the heater core that go down into the cab pillar. |
Posted By: Lonn
Date Posted: 25 Jan 2018 at 6:51am
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No valve up there? Then there must be a farmer added one down near the engine. ------------- -- --- .... .- -- -- .- -.. / .-- .- ... / .- / -- ..- .-. -.. . .-. .. -. --. / -.-. .... .. .-.. -.. / .-. .- .--. .. ... - Wink I am a Russian Bot |
Posted By: Blustery Knoll Farm
Date Posted: 25 Jan 2018 at 2:02pm
| Guess I need to start looking around. Where do the heater hoses connect to the engine? |
Posted By: Ron(AB)
Date Posted: 25 Jan 2018 at 6:17pm
| Thermostat housing and water pump usually.. |
Posted By: fourthgeneration
Date Posted: 26 Jan 2018 at 8:04am
| Hy-Capacity, AP Air, tractor joes sell the control valve. |
Posted By: Unit3
Date Posted: 26 Jan 2018 at 12:11pm
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One other place to look is to check that a hose is not pinched shut behind the battery tray. It happened to me. ------------- 2-8070FWA PS/8050PS/7080/7045PS/200/D15-II/2-WD45/WD/3-WC/UC/C |
Posted By: Blustery Knoll Farm
Date Posted: 29 Jan 2018 at 7:23pm
| I can't find a pinched hose or valve anywhere. With my IR thermometer, I get 140° out of the thermostat housing, and under 100° on the return hose to the water pump with the fan on full speed. This was just with the tractor idling on a 25° day. |
Posted By: Lonn
Date Posted: 30 Jan 2018 at 7:02am
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You won't get good heat up in the cab running tractor running at idle. Not enough push to get coolant up that far. Get yourself a new valve at the control in the cab or install shut off valves correctly at engine so you can shut it off in summer. ------------- -- --- .... .- -- -- .- -.. / .-- .- ... / .- / -- ..- .-. -.. . .-. .. -. --. / -.-. .... .. .-.. -.. / .-. .- .--. .. ... - Wink I am a Russian Bot |
Posted By: Tim NH
Date Posted: 30 Jan 2018 at 5:41pm
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I found on the 5/8 heater hose. A 3/4 Pex ball valve fits real tight in the hose. Then use regular hose clamps. I took the handle off and put it in the tool box. Tim ------------- 1950 WD 1959 D14 1955 WD45 1976 7000 B 207 |