Leaking Primer

[yankeetownboy]

Can anyone give me the AN or MS # for the o-rings on the Kohler primer.

I think I measure 7/16 id, 1/16 thick, 9/16 od? but can't seem to cross it

Jeff @ Indy
PA22-160
8434D

[taildraggerpilot]

Can anyone give me the AN or MS # for the o-rings on the Kohler primer.

I think I measure 7/16 id, 1/16 thick, 9/16 od? but can't seem to cross it

With the dimensions you provided, it would be something like an MS29513-013.

Some info I found indicated it should be an MS92513-012. It may be worth buying both and seeing what works best. I replaced mine a few years ago and can't remember the o-ring number I used, but it was likely an MS29513-xxx.

[Yellow Baron]

the balls and springs in the Kohler primer you get from:
Robert J. GeiszVice President of Sales and EngineeringEssex Industries, Inc.6 Sunnen DriveSaint Louis, MO 63143Office (314) 644-3000 Ext. 340Fax (314) 644-3857Cell (314) 852-3869

[Yellow Baron]

Spruce:

ESSEX O-RING FOR K2404-1/8
05-02174

[Yellow Baron]

you find the two on the shaft at Spruce (same place as the Essex primer) - the small one in the nose of the primer is a -004

you get it from

Harry Bolton
Sales Engineering Manager
Precision Associates, Inc.
1-888-724-0483
1-612-334-9132
1-612-334-9232 Fax
www.PrecisionAssociates.com

[smcnutt]

I've noticed that my Kohler primer is getting pretty hard to pump. It's not leaking but it's just hard to pull in/out. Do I need to pull it apart and replace the o-rings or can I just lubricate it somehow?

[Yellow Baron]

smcnutt,

do it two stages:

1) undo the big nut and get the plunger out - clean the gunk off, lubricate the o-rings with a bit of silicon grease and check if the needle/spring is working. Also check the tiny little o-ring in the back of the tube (look in from teh front with a torch) -sometimes it tears/sits sideways and blocks the hole

if that does not do it:
2) it is best to disconnect the whole thing, unscrew the two screws and clean the balls and springs behind it (watch they jump out), clean the gunk from the body and put is all back together with new o-rings all around

I did 1) and 2) every 4-5 years

[Yellow Baron]

... I did all of these above 5 years ago and then again now and found it was still leaking. i.e. extra fuel was being sucked into the engine through the closed primer ... (I checked by disconnecting the primerline and fitting it to a separate bottle) - so I am now waiting for new springs and balls to arraive to refurb the primer ...

[taildraggerpilot]

I spoke with the engineering rep. for Essex and he confirmed the O-rings for the primer pump are a size -012.

I didn't ask about the compound, but Viton would be best for both auto fuel and 100LL.

[walt.buskey]

Yellow Baron, this is good to hear, in a way. I recently purchased a 56 PA-22-150, and the previous owner was told, when he bought it seven years ago, that a) the primer didn't work, an b) don't run the engine "full rich" as it would foul the plugs.

My suspicion is that the primer pump was dribbling a bit of fuel in all the time, causing it to run just a tad richer than it normally would, hence " keep the mixture pulled out about a quarter of an inch all the time." I just wasn't sure if that were even possible, but it sure sounds like it is.

My instructor doesn't like this, and neither do I. Sounds like my suspicions were correct, and a rebuild kit is in order. This is a great site!