AC Forklift with D15 engine
Printed From: Unofficial Allis
Category: Allis Chalmers
Forum Name: Construction and other equipment
Forum Description: everything else with orange (or yellow) paint
URL: https://www.allischalmers.com/forum/forum_posts.asp?TID=209301
Printed Date: 11 Dec 2025 at 1:10pm
Software Version: Web Wiz Forums 11.10 - http://www.webwizforums.com
Topic: AC Forklift with D15 engine
Posted By: jpi72
Subject: AC Forklift with D15 engine
Date Posted: 10 Dec 2025 at 2:10pm
|
I own what I believe is an AC 610 forklift. It has a D15 series II engine (160 cu. in.) Was engine noted to have head problems? The third cylinder lost the keepers on the exhaust valve. We got the valve reattached and replaced with new keepers. Then to find out the that same cylinder has zero compression. After Christmas we will remove the head. Does anyone have experience with this problem? Joel
|
Replies:
Posted By: SteveM C/IL
Date Posted: 11 Dec 2025 at 8:29am
| If you dropped a valve I suspect you have a hole in a piston. How were you able to retrieve valve after loosing keepers? |
Posted By: jpi72
Date Posted: 11 Dec 2025 at 10:50am
|
The valve must have been supported by part of the combustion chamber beside the piston. I am fearful we have piston issues. We will know more when we lift the head. Joel
|
Posted By: Les Kerf
Date Posted: 11 Dec 2025 at 10:57am
|
Probably a hole in the piston or a bent/broken valve, maybe both; either way the head needs to off if you intend to fix it. You could blow air in through the spark plug hole with the piston at TDC (firing position) and listen for where the air leaks out. This really won't prove much other than verifying that you have a problem, which you already know
 |