Understanding what the hydraulic head, retaining clip is on a deuce...

AZK9

Active member
1,083
3
38
Location
PRC, AZ
Understanding what the hydraulic head, retaining clip is on a deuce...

After reading threads like, "Anyone interested in heavier duty hydraulic head button retaining clips?",
started by DavidWynmore... I was reminded (once again) that there really is a lot to learn about my M35A2. :roll:

During all my searching and reading... I had not come across... even a mention of a Hydraulic Head Retaining Clip.
I've also discovered that there were other folks who were also unaware that there even was such a part, that when broken...
could keep a deuce from even starting up again. :shock:

Sounds like a very critical part to my way of thinking. I'd say that there's probably a real need to keep a few
spares handy in the event of a clip failure!

You can find David's thread here: http://www.steelsoldiers.com/showth...er-duty-hydraulic-head-button-retaining-clips

Since I'm doing my best to get my deuce in shape to do a NJ to AZ trip this summer... reading, study, learning
and doing is how I've been spending my free time recently! :mrgreen: So... with that in mind, I'm still trying to gain a
deeper understanding of what role the little, hydraulic head, (button) retaining clip plays on a deuce.


Anyway... until I read David's thread, I had no clue (because I had not yet discovered this in TMs) what this part even was.
Because this site is a great place to gain knowledge reading TMs and threads many of us do just that. It's amazing how much
information is here! Still, at times... a question has to be asked:

where does it go and what does it do? i would be interested if it works on mine.
A couple of PMs to other SS members and then the post by 'red', (below) ... really helped me to begin to understand this issue.

If you look at your fuel injection pump there is the hydraulic head, where all the high pressure fuel lines run out to the injectors. If you pull that head off there is a plunger attached to it. A small metal 'button' is clipped to that plunger. The stock retaining clip is known to fall off, letting the button slide off of the plunger, resulting in no fuel flowing to the injectors.

He's proposing a stronger retaining clip, to fix the issue

Reading threads like this one often start me on another 'voyage towards understanding'.

Searching for more details about this 'clip' and the associated problems has turned up
more info that has helped to educate me even further.

Inject-button-0001.jpg:?: Question(s): Is the arrow (in this photo) pointing to an actual image of the
clip/button part being discussed? If so, is this clip one that appears to be in good shape, or
is it broken (missing something to it)?

There are additional 'clues' and documentation out there on other websites, but searching here
on SteelSoldiers has provided good reading too! :-D


If you need to know more about these clips... the following threads might be of some additional help:

Adrian A posted this:
http://www.steelsoldiers.com/showthread.php?112480-injection-pump-question-m35a2

Jhooah posted this:
http://www.steelsoldiers.com/showthread.php?74508-Need-Part-IP-Pump-Hydraulic-Head-Ring-Clip-needed-to-hold-button-on-rod

RustyStud posted this:
http://www.steelsoldiers.com/showthread.php?139813-Why-do-the-Hydraulic-Head-clips-fall-off


Without posts like these (linked above), I'd probably end up 'dead-in-the-water' along a lonely road somewhere in
'who-knows-where', instead of parked... safe-n-sound in my Arizona driveway!

--------------------------------------------------------------------------------------------------------------------------------
Feel free to add any information, or experience you may be able share.
The more we know, about this little retaining clip, the better.

Thanks in advance folks! [thumbzup]
 

mooresM35A2

Member
137
0
16
Location
Madison County IL
Looks like the part the arrow is pointing to is the button. We just had some fun last fall pulling the hyd. head off a duece at the museum. The exact same issue, the button fell off.
 

AZK9

Active member
1,083
3
38
Location
PRC, AZ
Looks like the part the arrow is pointing to is the button. We just had some fun last fall pulling the hyd. head off a duece at the museum. The exact same issue, the button fell off.
Wondering if anyone here on SS has photos of both a new, 'intact' button clip and...
also one that is a clear example of a 'broken' clip?

If so, please either post them here, or maybe provide a link. Although I've gained
a better understanding of this part, I'm still trying to learn more about it.

Thanks in advance! [thumbzup]
 

gimpyrobb

dumpsterlandingfromorbit!
27,707
396
83
Location
Cincy Ohio
I don't believe a "hulk" clip is needed. Consider the ones failing are 40ish years old, I believe a plain jane new one will serve us just fine.

Also, there is a belief that the plunger sticking in the hyd head bore is the reason for many clip failures.

Thats one of the best reasons to keep driving your trucks often!
 

AZK9

Active member
1,083
3
38
Location
PRC, AZ
Wondering if anyone here on SS has photos of both a new, 'intact' button clip and...
also one that is a clear example of a 'broken' clip?

If so, please either post them here, or maybe provide a link. Although I've gained
a better understanding of this part, I'm still trying to learn more about it. ...
From the standpoint of someone who has never experienced the inside of the HH, I'd like to fully
understand this critical component. Especially so I can make a roadside repair if it's ever necessary.

OK... As far as I can tell, the photo below shows (some of) the parts In-and-Around the
location where the button retaining clip can be found when it's all opened up.

HH-button-retaining clip.jpg

Still... It would be helpful, to me, if someone could verify what I have labeled in the photo,
to be correct. If there is something that is NOT correct, please point that out as well.


1........ Is the BLUE arrow pointing to the Spring Retaining Clip? (Yes/No)
2........ Is the YELLOW arrow pointing to the Button? (Yes/No)
3........ Is the RED arrow pointing to an (unbroken) Button Retaining Clip? (Yes/No)

Any help is appreciated. [thumbzup]
 

gimpyrobb

dumpsterlandingfromorbit!
27,707
396
83
Location
Cincy Ohio
Yellow and red are correct. The blue is the drive washer. Its like a mechanical fuse. If something is wrong, it will break to try and save other expensive parts.
 

AZK9

Active member
1,083
3
38
Location
PRC, AZ
... The blue is the drive washer. Its like a mechanical fuse. If something is wrong, it will break to try and save other expensive parts.
Thanks! [thumbzup] I can grasp that 'mechanical fuse' concept.

I'm also wondering if there is a top and bottom side to the button, or maybe it does not matter.

Many of the pics I've seen make me think it could be bowl-shaped.
 

AZK9

Active member
1,083
3
38
Location
PRC, AZ
Rounded on the HH stem side, flat on the cam side. ...
David... you got me hooked reading your thread (featuring JeepSinker)!
There's a lot of good stuff in there, but honestly, I would have missed
most of the valuable info had I read it even just a month ago, because
of where I was in my deuce education process.

I still do not know as much as I'd like, but... I have to pat myself on the
back :mrgreen: because I really knew nothing at all prior to my SS Self-Study! ;-)

It's a rewarding feeling to be able to read those posts and actually have
an understanding of much of it. :naner:

I'm getting there slowly, but... I am getting there! Thanks again!! [thumbzup]
 

frank8003

Well-known member
Steel Soldiers Supporter
6,430
4,920
113
Location
Ft. Lauderdale, Florida
Last edited:

Keith_J

Well-known member
3,325
559
113
Location
Schertz TX
Button retainers fall off because diesel now has a small amount of Biodiesel in it which reacts with water to form a gum. Clean your fuel system from tank to IP of water and gum. Fresh fuel and Diesel Mechanic in a Bottle are your best measures to prevent this problem. These engines need to run to operating temperature at least once a week. Modern diesels are even worse with Biodiesel.
 

USAFSS-ColdWarrior

Chaplain
Super Moderator
Steel Soldiers Supporter
18,169
3,687
113
Location
San Angelo, Tom Green County, Texas USA
Button retainers fall off because diesel now has a small amount of Biodiesel in it which reacts with water to form a gum. Clean your fuel system from tank to IP of water and gum. Fresh fuel and Diesel Mechanic in a Bottle are your best measures to prevent this problem. These engines need to run to operating temperature at least once a week. Modern diesels are even worse with Biodiesel.
I have stopped burning WVO in The ARK since having a clip failure and resultant button mutilation.

The "bragging rights" that come with "free" fuel just didn't justify the additional maintenance costs and consequences.

We now practice preventative measures to avoid gumming up the IP again.
 

Keith_J

Well-known member
3,325
559
113
Location
Schertz TX
To elaborate on the button retainer..when the plunger sticks, the cam which actuates the plunger loses contact with the button. Now there is space between the button and the base circle of the cam. The plunger spring can flip the button off the retainer. Remember, the plunger is actuated three times every engine revolution so it only takes a tiny bit of clearance between the button and cam to dislodge the retainer. The fit of the plunger in the head is leak tight, it will get sticky with the slightest amount of gum.

I don't get any compensation from Diesel Mechanic in a Bottle. But it saves me a ton of work. If you ever have a problem with the button retainer clip, the cost of this miracle solution is nothing compared to the labor. I used it straight instead of carb cleaner, just a few drops in the hydraulic head and fuel control lever bushing.
 

rustystud

Well-known member
8,617
671
113
Location
Woodinville, Washington
Button retainers fall off because diesel now has a small amount of Biodiesel in it which reacts with water to form a gum. Clean your fuel system from tank to IP of water and gum. Fresh fuel and Diesel Mechanic in a Bottle are your best measures to prevent this problem. These engines need to run to operating temperature at least once a week. Modern diesels are even worse with Biodiesel.

What he said :ditto: .
 

DavidWymore

Well-known member
1,583
122
63
Location
El Centro, CA
Almost finished stronger clip forming die still here on my desk. I/we have been busy, but will try to get the last of it figured out and squeezed into the schedule.
 
Top
AdBlock Detected

We get it, advertisements are annoying!

Sure, ad-blocking software does a great job at blocking ads, but it also blocks useful features of our website like our supporting vendors. Their ads help keep Steel Soldiers going. Please consider disabling your ad blockers for the site. Thanks!

I've Disabled AdBlock
No Thanks