I noticed I have a leak from my radiator cap when the engine is hot. I literally have a small puddle on the ground after the car sits for a few hours after shutdown. I have a SPECTRA PREMIUM CU828 replacement radiator if that says something. The cap seems kind of loose when installed. I have three different ones and they all do the same thing. I read in a thread before that you need to put the cap on "two clicks"(?).
Could this be my problem? Is just turning the cap on clockwise not enough (green line)? Should I push it down so the ears turn over the "stops" and they stay there so it seals tighter (red line)?
Thanks I found it on the internet and just drew those two lines so I can't take credit for that.
So I guess my new radiator trolled me because there's no other stop after that point. Meaning if I continue to "screw on" the cap it'll just come off since there's no more lip to hold onto. And I didn't remember how the original one went on... Hope this fixes my problem, will know tomorrow when I'll drive the car. Thanks.
If you look at the picture in my first post I guess you should see it. If the cap lip is already under the stop after the red line and you continue to turn it clockwise it'll just fall out like it was never even screwed on. I wonder if that's just a design thing of the new radiator or am I missing a piece there or I don't know...
EDIT: Found a good picture of a cap on the filler neck (not a Fiero though), maybe this makes more sense?
[This message has been edited by cebix (edited 06-08-2020).]
Here's the neck on my radiator, but I don't know if it is original or not. The first stop requires the 'push down' and the second is just at the end of the cam. Are you continuing to 'push down' after stop 1? If so that might allow one to go beyond stop 2.
Here's the neck on my radiator, but I don't know if it is original or not. The first stop requires the 'push down' and the second is just at the end of the cam. Are you continuing to 'push down' after stop 1? If so that might allow one to go beyond stop 2.
Exactly. I didn't notice a "first stop" on my radiator or if there is one it doesn't need any pushing down of the cap. All my different caps screw one freely. So what I did was actually put the rad cap lip over the second stop on your photo. Before that the cap kind of wobbles with very little force. Maybe I have to bend my lips a little so they seal tighter?
EDIT: All right I see where I messed up. The first diagram is wrong. Here's an updated one and the blue area is the stop I meant to point out. Sorry for that. So the cap should seal before that stop?
[This message has been edited by cebix (edited 06-08-2020).]
Yes, sorry for that, I edited my post above, the diagram in the first post points to the wrong stop. My rad caps go over that 2nd stop easily with some hand pressure on it. If it turns out it seals well with the lip over the second stop can I run the car that way? Or is there some bending or other risks involved?
Where's the Stant SuperStat you said you had ordered and installed?
[QUOTE]Originally posted by cebix:
Ordered a SuperStat 45819 again, let's see what it does. Yeah, again from Rockauto. Should be here by Friday...
[/QUOTE]
That's in the rear under the thermostat cap. Does that relate in any way to my radiator cap in this situation? Thermostat cap is also new AC DELCO now since my Stant cap leaked... AC DELCO has a much wider and thicker gasket from what I noticed. Was a pain to screw on the housing.
Sorry, I'm all messed up here. This is what I get for trying to multitask.
I don't understand though how you can turn the rad cap past the second stop. Either you've got the strength of ten men, or your rad cap and/or your radiator neck are poorly designed.
[This message has been edited by Patrick (edited 06-08-2020).]
Sorry, I'm all messed up here. This is what I get for trying to multitask.
No worries, I appreciate all the help. So I guess I can bet on the radiator filler neck being crap? Might just fabricate another gasket to seal that up or bend those rad cap ears a little.
The cap seems kind of loose when installed. I have three different ones and they all do the same thing.
quote
Originally posted by cebix:
So I guess I can bet on the radiator filler neck being crap?
Perhaps the rad cap is to blame? You've said you have three of them. Are any of them new? If so, what is it exactly? As you've no doubt been made aware of at some point, the rad cap for a Fiero needs to be a non-vented one.
quote
Originally posted by cebix:
I noticed I have a leak from my radiator cap when the engine is hot. I literally have a small puddle on the ground after the car sits for a few hours after shutdown.
[This message has been edited by Patrick (edited 06-08-2020).]
Yes, 3 caps. One is old, probably original, one is a motorad safety release and the third one is a Delco. Those two were bought less than a year ago. All 3 were on my original radiator and I don't remember there being a leak from the cap in that original radiator. Unvented caps all 3.
All 3 were on my original radiator and I don't remember there being a leak from the cap in that original radiator.
With a new radiator, I believe you should be using a new non-vented cap. The sealing surface for the cap on this aftermarket radiator is no doubt slightly different than on the original factory radiator. The sealing area on all three caps might be "imprinted" with the shape of the old rad.
To tell the truth, upon hearing this revelation, I'm not surprised the caps all leak!
Use Stant Caps. They made and still make many OEM caps for Ford GM and more. See my Cave, Radiator Caps
Stant caps are made w/ "The SWIV-EL design allows the cap to be installed and removed much easier than conventional radiator caps." Basically means top will still move while rubber seals won't and you can get a cap on and off.
Stant's LEV-R-VENT™ and related caps are ok but have problems. Lever part leaks if open often. On Fiero (and others) the level may have clearance problems w/ the hood and right hinge area. I stopped use them on anything.
Yes, Rad Tube has 2 spots for the cap. The 2nd step w/ final hard stop is Full Close is to operate the system. The 1st step w/ a small stop is to release pressure when trying to remove it w/o blowing the cap off. This small stop may not work well for several reasons and can turn the cap complete off and have hot coolant burn you. This 2 step design is way old, like Many Decades at lest, and still used on most car.
------------------ Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should. (Jurassic Park)
Thanks. I guess it's a simple design but problems can arise everywhere and anywhere. I saw some posts on other automotive boards and I see it's common for people to shim radiator caps with rubber gaskets and bend those ears. Especially if something like an aftermarket radiator or cap comes into play.
That's very odd.
Are any of them new? If so, what is it exactly? As you've no doubt been made aware of at some point, the rad cap for a Fiero needs to be a non-vented one.
