Author Topic: Going crazy with this cool head 😡😡😡 (Read 4989 times)

Powerstroken · « **on:** April 22, 2015, 05:06:07 PM »

[h=2][/h] So I bought a cool head that was set up for o-rings and I can not get any to fit.

1st pic) Here are the ones it came with. Dome ring fits great outside ring to big.
2nd pic) these are esr rings dome ring to big and outside ring too small I assume it will fit if stretched but won't stay
3rd pic) bdt rings both a little to big

please let me know if I am doing something wrong I am getting pretty aggravated have been trying to find rings for 2 weeks now and it's getting old. Also tried local hydraulic shops and they couldn't find anything to fit it's just getting old.
sorry to rant

Tbone07 · « **Reply #1 on:** April 22, 2015, 05:25:35 PM »

The rings in the first picture look like the ones i used on my cool-head (size wise that is).

I used white lithium grease and ran my finger along the o-ring, that outside o-ring will fit

beobe99 · « **Reply #2 on:** April 22, 2015, 06:08:30 PM »

I recently took a snow blower carb apart, then left the pieces in the cold garage for a couple days until I felt like working on it again.. Anyway, the O-ring for the bowl (that was okay to re-use) seemed to of grown.. Took it outside and let it warm in the sun and it now fits.

I'd take the outer ring in the first pic and use a hair drying on it for a second or two.

Powerstroken · « **Reply #3 on:** April 22, 2015, 06:34:48 PM »

I was thinking of putting it in the freezer thinking the cold would make it shrink. Being none of the ones from manufacturers fit does that mean they were probably machined for orings

broken1 · « **Reply #4 on:** April 22, 2015, 09:08:43 PM »

Quote from: Tbone07;53543

The rings in the first picture look like the ones i used on my cool-head (size wise that is).

I used white lithium grease and ran my finger along the o-ring, that outside o-ring will fit

X2, those are the same as mine also in the 1st pic... I wipe the o-ring down with paint prep cleaner on a terry cloth & clean the groove in the head really good & the o-ring should stick long enough to set it on the cylinder.

Jerry Hall · « **Reply #5 on:** April 22, 2015, 11:40:19 PM »

I believe Cool Head uses O-rings that are .070" cross-section and ESR uses metric (2 mm) cross-section o-rings. Metric o-rings use a different gland dimension because their cross-section is 2mm (.080").

Silicone 0-rings will expand when exposed to gasoline, oil or antifreeze. Viton o-rings are not affected by gasoline, oil or antifreeze.

Tbone07 · « **Reply #6 on:** April 23, 2015, 08:59:26 AM »

Quote from: Powerstroken;53549

I was thinking of putting it in the freezer thinking the cold would make it shrink. Being none of the ones from manufacturers fit does that mean they were probably machined for orings

My brand new ones from Duncan looked exactly the same. I wouldn't freeze or heat them or anything, little bit of grease and they'll go right in

Also, you don't need to send your head or o-rings anywhere (or buy new ones). The ones you have will work fine

JesseA420 · « **Reply #7 on:** April 23, 2015, 10:09:44 AM »

just use the ones from pic 1 like everyone has mentioned. custom o-rings are NOT needed for a standard coolhead. some people.........

Rupp250 · « **Reply #8 on:** April 23, 2015, 12:12:06 PM »

Little vaseline will hold that first one in no problem.

udontknowme · « **Reply #9 on:** April 23, 2015, 09:25:16 PM »

im no expert on orings but im sure theyre supposed to be nearly the same size as the groove. if you have to stretch them very much i think it would be bad as it seems like that would decrease the orings crossection and not fill up the groove correctly , there for not sealing correct when head is bolted on. orings hanging over the groove doesnt seem good either.

Tbone07 · « **Reply #10 on:** April 24, 2015, 10:46:18 AM »

I'd much rather have the o-ring a little bigger, if you have to stretch it out I would think it would take away a lot of it's ability to "swell" and get a good tight seal.

The rings in the 1st or 3rd pic should work

F-Red · « **Reply #11 on:** April 24, 2015, 01:03:44 PM »

Just installed a set for my ESR 350 from Eddie. The inside one fits great, the outside, just a hair small. A little stretch, pop that cuch right in! :smug:

udontknowme · « **Reply #12 on:** April 24, 2015, 09:04:17 PM »

2nd pic looks horrible. inner oring is way to big, outer is way to small. first pic appears to be best. inner seems to fit good, outer is just a tad big but would likely work fine, maybe. on the oring engines ive seen there is very little pulling or pushing of either oring. maybe esr has changed suppliers over time and the newer orings dont quit match the original oring grooves

Hawaiiysr · « **Reply #13 on:** April 24, 2015, 11:01:33 PM »

I got ESR orings for my proX heads. I know they didn't fit well. I better go check