Community Forums

spat · 10-18-2009, 08:29 PM

I have a 2002 WH Chassis with an RC33 radiator cap that I cannot remove. I can turn it cc one notch, after that, I can't budge it, even with a large pair of water pump pliers. Is there something I'm over looking here. Could it require a special tool?

I want to change the coolant and install a new replacement radiator cap. Thanks.
Steve

DriVer · 10-18-2009, 08:35 PM

Quote:

Originally Posted by spat

I have a 2002 WH Chassis with an RC33 radiator cap that I cannot remove. I can turn it cc one notch, after that, I can't budge it, even with a large pair of water pump pliers. Is there something I'm over looking here. Could it require a special tool?

Steve, You have to push down and turn the cap. That's all there is to it! Please put the pliers away!

Rocky Larson · 10-19-2009, 05:38 AM

It can be a hard remove. I couldn't get it off and others with more experience than I tried. However, it is just a PUSH and twist. Once off you will see the locking tabs that are causing the issue. They can be bent slightly without effecting its use and making it easier to remove. OEM replacement can be hard to find.

DriVer · 10-19-2009, 05:50 AM

Quote:

Originally Posted by Rocky Larson

It can be a hard remove. I couldn't get it off and others with more experience than I tried. However, it is just a PUSH and twist. Once off you will see the locking tabs that are causing the issue. They can be bent slightly without effecting its use and making it easier to remove. OEM replacement can be hard to find.

This is the cap that I received from my AC/Delco dealer as a direct replacement for the RC-33.

The arrow (6 o'clock) points to the recovery tank hose.

Clay L · 10-19-2009, 09:35 AM

My 2004 cap was a bear to remove also. I had to remove the air intake horn to get in postion to take it off - and I knew about having to push down and turn.

Duner · 10-19-2009, 10:06 PM

I had mine off last month and here's my tip.....

Using the palm of your hand, push down very, very firmly and rotate your wrist. No need to get a tight grip with your fingers.... the key is getting it pushed down far enough. You will feel it move down, but you have to get it a little bit further down for the cap to miss the little tabs.

I have the Brazel's CAI so I didn't have the air intake "tuba" in the way.

Good luck,
Bill

DriVer · 10-20-2009, 07:01 AM

Quote:

Originally Posted by Duner

Using the palm of your hand, push down very, very firmly and rotate your wrist. No need to get a tight grip with your fingers.... the key is getting it pushed down far enough.

Bill, that's exactly right.

I believe that we also need to introduce to the members why it's so important to have a look see inside the radiator periodically. Please review the material that is accessible using the link below....

Coolant Overflow Reservoir

It's not just a radiator cap it's quite possibly the single most important component to the cooling system aside from the water pump. If you change your cololant good run is replace both the thermostat and the radiator cap.

Deaop · 10-20-2009, 10:24 AM

Hi,
I had to stand on a box to get enough pressure to remove mine. Use the palm of your hand, push down and turn counterclockwise. you may have to do it twice to get past the stops.

I replaced mine with a RC-27 15lbs from Chevy dealer. The RC-33 is no longer made. Make sure the arrows line up with the overflow hose.

Good luck

Ron

DriVer · 10-20-2009, 03:52 PM

Quote:

Originally Posted by Deaop

I replaced mine with a RC-27 15lbs from Chevy dealer. The RC-33 is no longer made. Make sure the arrows line up with the overflow hose.

Ron, The replacement cap I obtained (shown) is an 18 psi cap. That's the one you need to run with the Workhorse Coolant Recovery tank.

Deaop · 10-20-2009, 05:20 PM

Driver,

The RC33 I took off was a 15psi cap. I replaced it with a 15psi cap from Chevy.

Omey's site lists an RC81 #25661990 Ac Delco at 15 psi. I would think anything that fits and is 15 to 18psi would work. But I don't know this for sure.

Mine was for a 2002 Bounder.

Thanks

Ron

DriVer · 10-20-2009, 08:07 PM

Quote:

Originally Posted by Deaop

The RC33 I took off was a 15psi cap. I replaced it with a 15psi cap from Chevy.

Ron, Upon further review and after investigating the nominal pressure in the 8.1L engine's cooling system, the RC-33 is in fact as you stated a 15 PSI cap.

I will be going to my supplier in the morning and try to locate a 15 PSI cap.

In my investigation it is clearly listed that 20PSI of pressure will damage the system. Running an 18 PSI cap is just too close for me. Glad we've had this discussion!

Deaop · 10-22-2009, 12:30 PM

Spat,

Did you get the cap off? Hope you did and have new anti-freeze in by now.
If you need some help just ask. I am sure someone will lend a hand.

Good luck

Ron

laws224 · 08-10-2011, 06:48 PM

I could not get the RC-33 cap off of my 2002 8.1 engine either. I was ona stool and pushing and turn hard, thought I was going to break something. And if you look at page 87 of the Workhorse manual it makes a very specific point of " do not press down on the cap. The other thing about this cap is that it has a anti-corrosion anode built into it. I had to cut and bend mine off. Put a crossover STANT 10230 on and almost had to cut it off. Will look at some of the suggestions mentioned here, thanks

DriVer · 08-11-2011, 10:00 PM

Quote:

Originally Posted by laws224

I could not get the RC-33 cap off of my 2002 8.1 engine either. I was ona stool and pushing and turn hard, thought I was going to break something. And if you look at page 87 of the Workhorse manual it makes a very specific point of " do not press down on the cap.

The cap has to be pressed down to clear the safety catches that are built into the fill neck that prevent an explosive scalding event from occurring in the event of a sudden release of the cap.