Heater box rebuild ALMOST done, but wait...

[evoldog]

A. The bowden cable that goes through the whole in the bolt to control the valve broke off inside the bolt. So there's a little piece in there and now the bowden cable is too short to control the valve fully.

B. The special bolt that has the little hole in it broke in half while I was removing the nut. There's not enough thread to put the washers and bolt back on.

C. I'm guessing I need a new bowden cable. But it's not clear how I would replace just that part. The control lever end is mashed between two metal disks along with another cable that controls a flap. Do I have to replace the whole control lever unit? (wet stuff in picture = lube overspray)

Pictures attached for reference. Please let me know what I should do and/or which parts I should order. Part numbers? I'd like to get stuff in my hands in Portland before next weekend so I can finish this project up.

Thanks!

[ClayW]

At the heater valve, you'll need to replace the special bolt. It might be easier to find a used lever and just replace that.

As for the cable, I used a lawn mower choke cable that I got at Home Depot for around $10. You can trim them to length and it's the right size.

[MikeWooldridge]

At the heater valve, you'll need to replace the special bolt. It might be easier to find a used lever and just replace that.

As for the cable, I used a lawn mower choke cable that I got at Home Depot for around $10. You can trim them to length and it's the right size.

To further elaborate on the cable: There is no need to remove the sheath...just run a new cable through it, make a circle on one end to attach to the bowden end. On the heater valve end, in a bind you might improvise a smaller bolt with the cable end stuck in the hole with the bolt.

[1453aalapapa]

A. The bowden cable that goes through the whole in the bolt to control the valve broke off inside the bolt. So there's a little piece in there and now the bowden cable is too short to control the valve fully.

B. The special bolt that has the little hole in it broke in half while I was removing the nut. There's not enough thread to put the washers and bolt back on.

C. I'm guessing I need a new bowden cable. But it's not clear how I would replace just that part. The control lever end is mashed between two metal disks along with another cable that controls a flap. Do I have to replace the whole control lever unit? (wet stuff in picture = lube overspray)

Pictures attached for reference. Please let me know what I should do and/or which parts I should order. Part numbers? I'd like to get stuff in my hands in Portland before next weekend so I can finish this project up.

Thanks!

you got more problems than you think. that bolt is nla. you better start scrounging NOW, cause anyplace that has one is going to want big bucks just to take it out. 64 11 4 674 219

[evoldog]

Yes, that idea to improvise something at the valve end makes sense. No need to hunt down a crazy old bolt with a hole with it. I could come up with a pretty robust system with washers, where the bowden cable goes through the hole in one of the washers. Would work great, right?

I'll see if I can figure out how to put a lawnmower cable from Home Depot in there, attached at the control end... just cut the old one, then try to coil the new cable underneath that round metal bit that's holding the other bowden cable?

Any other ideas/thoughts welcome...going to try to do this tonight and avoid renting a car when I have to pick up my kid next. She's too little for the motorcycle!

[Mike Self]

it attaches to the heater control lever. That cable assy is actually one piece, with two cables fastened together at the lever. One opens the water valve, while the other simultaneously closes the "fresh air mixer flap"--the little door that bypasses the heater core underneath the fan. That setup means that as you increase the hot water flow, you gradually close the fresh air flap, forcing more and more air to go through the heater core before exiting into the passenger compartment.

You may be able to replace the damaged cable (that goes to the water valve) alone but make sure the two cables still work properly when you do. Otherwise you'll either never get very warm air when the heater is set to hot, nor will you get very cool air when the heater is set to cold.

As for the clamp bolt at the valve end, the easiest fix might be to take a small bolt (that will pass thru the lever on the valve), form a loop in the cable end that will pass around the bolt's shank, the double nut the bolt so that it will rotate on the lever without falling out.

If you don't get it fixed this evening, just run a connector pipe between the two heater hoses and you can drive the car without the heater.

cheers

mike

[SteveJ]

The control cable is not that pricey of a part from the dealer/Blunt. As I recall, maybe $25. At the control lever it is heald on with an E-clip. Pop that off with a small flat blade screwdriver, and then go chase it down. The cable assembly- both cables- will slide up and off the post.

Unfortunately, you have now heard about the bolt.

You can drill a hole in a bolt and use that, however, it does need to pivot while it it is on the lever arm(loose). It also has to snug down on the cable (tight). I used a bolt, drilled a hole under the head. I then used a nyloc nut and cinched it down on the control cable. After that I used another nyloc nut and attached it to the control arm.

[evoldog]

Great tips in here. Thanks!

So, if I order the heat control cable from the dealer, it's just the one cable. But the two cables are attached together at the control arm, sandwiched between two round metal bits (fused together?) under the e clip. How would I replace just one cable?

I'm looking at part 64111352124, identified as #22 in the picture:

http://parts.bmwofsouthatlanta.com/showAssembly.aspx?ukey_assembly=254761

Please let me know how to mount that in with the other cable properly, because I'd like to order this part today!

RE: the other end... there's got to be a "best practice" solution for how to avoid hunting for old rusty bolts with holes in them.

Drilling a hole in a metal bolt sounds awesome... but almost impossible. Jesus! I don't have a drill press.

But I get that it will have to rotate. And it needs to be adjustable so I can't just wrap the cable around the bolt.

I guess I could figure out a system with washer that could do that. If anyone else has come up with a robust hack, please let me know... and post pictures!

[evoldog]

This seems promising... I could order a new "pin bolt" from Maximillian for $3.53:

http://www.bmwmobiletradition-online.com/bmw/showparts.do?model=2515&mospid=47139&btnr=64_0851&hg=64&fg=25

I found the details in this thread...

http://www.bmw2002faq.com/component/option,com_forum/Itemid,0/page,viewtopic/t,319650/view,next/sid,78cef7b3b6cdcaca75282a12ccc88c0a/

Still figuring out the bowden cable mounting...

[JohnS]

If Max doesn't have that "pin bolt" available, I believe that JayMic in the UK does. Good luck,

John

www.jaymic.com

[SteveJ]

Item #7 (-484) is the double cable that controls the heater valve. Unfortunately, the heater box would have to be opened to unclip the other half of the cable for replacement. It sounds as if you were looking at making the heater valve cable into a single cable. Yeah, you'd have to modify the dash control lever. It may be do-able, but you'd have to see how things move in behind the dash. Look for interference.

Wrapping the end of the cable around a bolt at the heater control valve arm may not be such a bad idea. Brand new, there is possibly enough flexibility and workable legnth at the cable end to form a loop (loop and a half) to fit over the end of the bolt. It would fit loose enough to act as the needed pivot. The whole deal is that this cable acts as a push-pull.

[evoldog]

I just ordered the pin bolt and the double cable that controls the heater valve. Since I already have the heater box out of the car I might as well finish the job properly and just open it back up to attach both cables.

[jgerock]

Presenting the famous pin bolt (mentioned in an older thread)

Associated washers

Nut

I should be scavaging old heater box parts for stuff like this.

[evoldog]

Ok I'm going to bump this thread into Alert Level Orange.

Max/MT: pin bolt indefinitely back ordered.

JayMic: £30 to get the bolt here in time for my planned install 10/5.

Anybody have an extra pin bolt lying around? Who's been stockpiling all the pin bolts??

I'm putting the heater box back in next weekend no matter what, just would rather not fiddle with installing the bolt in that tiny opening after the fact.

[Catman]

There are a bunch of choke kits that are after market that come with an assortment of those bolts and set screws that can be used to fix this.You still might have to put on your thinkn' hat but this is not a big deal this is a little bump in the road.

Manual choke cable kit . Have to have one to put on any manual choke carb.The barrel in the kit is brass I have used them sense I was --- lets say much younger.

Catman