8070 Problems
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=42527
Printed Date: 24 Aug 2025 at 4:32pm
Software Version: Web Wiz Forums 11.10 - http://www.webwizforums.com
Topic: 8070 Problems
Posted By: Sonlight
Subject: 8070 Problems
Date Posted: 22 Dec 2011 at 3:45pm
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New on the site. We just bought a FWA 8070 in May. Started running very rough and noisy. We've rebuilt 2 301's but not real familiar with the 426. The cooling system was under pressure, some of the hose connections were leaking. No coolant in the oil though . Approx 4600 hrs. Trying to do some diagnostics before tearing into it. Any advice or suggestions would be great! Thanks.
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Replies:
Posted By: Kevin in WA
Date Posted: 22 Dec 2011 at 6:12pm
| Head gasket blown out between cylinders, Bad Injection pump also could be causing rough running. |
Posted By: Brad(WI)
Date Posted: 22 Dec 2011 at 6:26pm
| Is it using any anitfreeze, beside what is leaking? Head gasket, valve lash out of whack, injectors/pump, broken/bad piston ring(s) could be some possibilities. Turbo will be low power and lots of smoke. Not sure if intercoolers ever go bad, that might put extra pressure on coolant. Most likely a head gasket though. Run with radiator cap off and watch for bubbles, good sign of a bad head gasket. |
Posted By: Orange Blood
Date Posted: 22 Dec 2011 at 8:03pm
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The rough and noisy part bothers me, while the pressure in the cooling system above normal, is an issue, I have never had a blown head gasket cause the rough and noisy, not saying it can't but I wonder if there is something else that is in need of repair as well, in addition to a head gasket? First thing I would do is change the fuel filter, make sure that pump is getting all the fuel it wants, then crack the injector lines one at a time to see if each and every line causes the engine to have a slight change in RPM and starts to miss. Is is a power dirrector or power shift. Sometimes a noise in the front of the tranny can sound like and engine noise. Do changes in clutch position, gear selection, or hydraulic pump load change anything? ------------- 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: TREVMAN
Date Posted: 22 Dec 2011 at 8:53pm
| Cylinder liner cavitation, pressurizing waterjacket. Get oil analysed. Does it have a water filter? Last time it was changed? how many hours? If it is above, time for a rebuild, Trev. |
Posted By: MACK
Date Posted: 22 Dec 2011 at 9:56pm
| If it has 4600 hrs, it is past time for a set of bearings. Could be a piston burned down the side. If it is a burned piston go all the way with a complete overhal. MACK |
Posted By: Sonlight
Date Posted: 22 Dec 2011 at 10:33pm
| Thanks for all the input. Yeah we were planning on doing rod bearings and bolts this winter anywy because the threads can stretch ?? Did a complete service ,flushed cooling system , and all filters in the spring. Got a feeling it could be more then gasket. |
Posted By: injpumpEd
Date Posted: 23 Dec 2011 at 9:20am
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A 426 is just a larger version of a 301. a lot of similarities. An 8070 FWA is definitely worth the overhaul.
------------- 210 "too hot to farm" puller, part of the "insane pumpkin posse". Owner of Guenther Heritage Diesel, specializing in fuel injection systems on heritage era tractors. stock rebuilds to all out pullers! |
Posted By: 427435
Date Posted: 23 Dec 2011 at 10:37am
This would be my guess. If the water filters weren't changed religiously on the intercooled 426's, cylinder liner cavitation was a given. ------------- Mark B10 Allis, 917 Allis, 7116 Simplicity, 7790 Simplicity Diesel, GTH-L Simplicity Ignorance is curable-----stupidity is not. |
TREVMAN wrote: