body and interior Broken heater Valve?

[landon]

Got the 02 back on the road for spring a couple of weeks ago after doing heater box rebuild. New flap foam seals, bushings, cleanup etc.and installed new valve rebuild kit from blunt. Everything was working pretty nicely. Did a road trip today and turned on the heat lever and just got cold air. Vents all working OK. Checked the cable operation at the valve and it looks OK. Manually moved the lever on the valve and it feels fine. The inlet hose is hot and the outlet hose is cold. No leaks anywhere.

 

Are the internals for the valve broken? I polished the inside of the valve body smooth and greased everything. Seems like the plastic is not rotating to open the valve but not sure how that can happen?

[jgerock]

Did you drive and test the heater right after you rebuilt the box - or is this the first time?  Maybe you put the lever back on the valve in the wrong position.  

 

Hose from cylinder head to valve is hot - but return hose from heater core is cold?

 

Hose from cylinder head to valve is hot - what about the short hose after the valve?

[M3M3]

See the article on how to rebuild a heater valve.

[Mike Self]

It's also possible to install the lever on the valve backwards (yet another hard-learned lesson!), so that when the dash lever is set to cold the valve is open to admit hot coolant, and vice versa.  Also, if you have a later valve with the plastic innards, the square end that the lever fits over (and is bolted to) on the outside of the valve can be worn so when you move the cable and lever, they move, but the valve itself doesn't.  

 

mike

[landon]

The heater box and valve were tested prior to re-install. The heater core was pressure tested. The car was driven for a week and a half with normal operation. Hot air when the in the heat position - cold air when in the off position. I followed the heater valve rebuild article on this site. I was careful to not install the arm backwards and normal operation showed that this part of the assembly was correct. I do not get heat in either position now. It seems to be blocked at the valve? With the new rebuild kit parts it seems improbable that the arm can rotate and not move the plastic valve with it. Just looking for some insight before I remove the valve again. 

[landon]

Did you drive and test the heater right after you rebuilt the box - or is this the first time?  Maybe you put the lever back on the valve in the wrong position.  

 

Hose from cylinder head to valve is hot - but return hose from heater core is cold?

 

Hose from cylinder head to valve is hot - what about the short hose after the valve?

The return hose is cold. The inlet hose is hot. The valve is hot and the small hose after the valve is hot / warm also. I think this is due to it's close attachment to the hot inlet hose. Hot water is not getting into the core. 

['76mintgrün'02]

My valve quit working and it turned out that the little screw that holds the arm on had come loose.

 

EDIT:  probably not your problem, but it made me so happy that I felt compelled to share it (again) here.  

Edited June 10, 2015 by '76Mintgrun'02

[M3M3]

The heater box and valve were tested prior to re-install. The heater core was pressure tested. The car was driven for a week and a half with normal operation. Hot air when the in the heat position - cold air when in the off position. I followed the heater valve rebuild article on this site. I was careful to not install the arm backwards and normal operation showed that this part of the assembly was correct. I do not get heat in either position now. It seems to be blocked at the valve? With the new rebuild kit parts it seems improbable that the arm can rotate and not move the plastic valve with it. Just looking for some insight before I remove the valve again.

  

The return hose is cold. The inlet hose is hot. The valve is hot and the small hose after the valve is hot / warm also. I think this is due to it's close attachment to the hot inlet hose. Hot water is not getting into the core.

That does not sound like a valve issue. House coming out of the valve would be cold.

Heater core blocked? It's the car running cool? Possible air bubble in box core? I would Jack front of car up high and bleed cooling system again with valve open.

[PaulTWinterton]

Heater core blocked? It's the car running cool? Possible air bubble in box core? I would Jack front of car up high and bleed cooling system again with valve open.

 

+1 

[landon]

  

That does not sound like a valve issue. House coming out of the valve would be cold.

Heater core blocked? It's the car running cool? Possible air bubble in box core? I would Jack front of car up high and bleed cooling system again with valve open.

I will try this. I did not think a bubble would present itself after a week of driving. And I'll check the temp of the short hose again but it all felt warm and that seemed reasonable since it is attached to a metal valve body that is in contact with the hot inlet hose.  

[PaulTWinterton]

More than a bubble.  No water at all.  You can also park on a steep incline, remove the rad cap and squeeze the upper rad hose to burp the system.  If the water level in the rad is low(ish), top it up and continue to burp.  Squeeze other hoses as well to encourage water flow.

[OriginalOwner]

My "burp" method:  with engine cold (or cool enough to remove the radiator cap), I remove the radiator cap and open the heater valve.  I top up the radiator to "nice and full" ..... this backfills that top inlet hose to the radiator and "drains" coolant back into the head.  I start the engine (radiator cap NOT installed) and let it get up to temp.  Once the engine is at temp and coolant is circulating nicely, I squeeze the hoses a couple of times just to be polite.  

      If the radiator is still really full, I'll draw out some coolant to drop the radiator level just a little bit.  I then install the radiator cap.  Never had a bubble problem, and never had to do the "incline" method.  

 

 I did this method just last night.  Everything is working just fine, and coolant is flowing through the heater core per design.  I checked it this morning and had to add about 1 cup of coolant (hot coolant expands, so check coolant level after the engine cools sufficiently to remove the radiator cap).

 

Cheers,

 

Carl

Edited June 10, 2015 by OriginalOwner

[BLUNT]

Landon  Please report back with findings. Weve sold 75 of these without one issue. Id like to know what you find

[landon]

Landon  Please report back with findings. Weve sold 75 of these without one issue. Id like to know what you find

Yes, I definitely will. The design seems fool proof - but then again I worked on it.......

I jacked up the car last night and bled the coolant system - no bubbles showing up but I am going to try again as the outlet hose is still cold. Engine is running normal temps and like I said in the original post- the heater was working fine last week.