BC Broncos A/C Evap expansion valve hitting body/firewall

Just mounted up the BC Broncos A/C Evaporator case in the Bronco tonight and I'm concerned about the Expansion Valve resting on the body/hump/firewall as shown in the pic. Anyone else with the BC A/C kit....is your expansion valve head resting on the body like mine is in the pic? If so, what sort of adjustments did you make so it's not resting on the hump/firewall area?

I'm assuming it should not be this way, but no matter which way I shift the evap case around, it's still resting on the hump/firewall sheet metal. It seems like over the long term this would break the expansion valve.

Suggestions? Thanks in advance.


One more....I received a few bags of hardware, bolts, nuts, screws, etc with the kit. Nothing in the instructions that I've found details what goes where and which hardware is to be used for which pieces. Is there a detail on this available?

I should also add....it's not as easy as or super feasible to just raise the whole evap case given the situation at the top. You can see how close to the upper cowl the evap case is currently.....and there needs to be enough room to attach the hoses going to the dash and defrost vents. The hoses come out the top of the evap case.

I had the same problem when I installed mine. I actually pushed it up just a little and bent the tube a very few degrees more and it fit. Tight but it fit. I was very careful to make sure the tube didn't crimp and i checked with the local AC guru to make sure it was ok

I may have messed up by doing this but I really didn't see any other way without moving the kick panel or cutting a hole in it.

I'm sure Chuck will chime in when he has a chance.

If you don't want to bend it you could put a dent or hole in the kick panel where the fan box touches and slot the holes a little bit. Just a thought maybe not a good one but a thought.

Hope this helps

Thanks for weighing in with your experience. Are you saying you bent the tube coming out the top going to the vents, or you bent the small diameter cap. tube going to the expansion valve head?

I'm surprised this is not mentioned in the instruction sheet since it is so tight a fit, and given the importance of not damaging the expansion valve.

The fit was definitely crazy tight. Here are a few pics I have. Ill see if I can find more from better angles. I did have "rework" some of the floor to get this thing in properly. By rework I mean lots of hammering, reshaping, a bit of welding then some seam sealing.

It is true that things are tight. I tried to put the most I could fit in the space. Over the years I have come across a fitment problem a few times. It is hard to see what the problem is from a picture so please disreguard any that do not apply to you. The evap was designed to be used with stock firewall and floor and with stock firewall insulation. I think the stock insulation holds the evap out from the firewall about 3/4". The fan housing fits in the "pie plate" cover that covers the vent hole in the pass. kick panel. I worked with a guy that had welded this hole up while doing his resto. I did not realize this at first and put a lot of work into figuring this one out. The lesson is if you change anything it may change other things that would seem unrelated. I know I did not say in the instructions that the "pie plate" had to be used or that the insulation had to be used but I just never thought about either being removed. Insulation is important for A/C to work well but I didn't put that in the instructions either The other day a guy called and told me he had to add 1/2" of spacer to move the evap out to clear the exp. valve. Later I was thinking about why his floor would be diff. The insulation is the only thing I can see that would be diff. Hope that helped, if not give me a call.
PS, The expansion valve can be rotated but be sure to use 2 wrenches or you will damage the core.

Thanks for the other pics and info NY-Bronco and Chuck. I took a few more pics showing how tight the fan already is in the pie plate cover. I have firewall insulation as well. I don't know that it can shift any further into the pie plate as I had to really push it hard to get it over this far so the 2 front mounts fit thru the existing heater box holes in the firewall.

I have everything Chuck mentioned as necessary....pie plate cover, & firewall insulation. With the exp. valve head sitting on the body sheet metal, do I need to try again to get that exp. valve up off the sheet metal, or will it last resting on the sheet metal? Was this sentence in your reply regarding my pic, or some other pic in the BC instructions or on BCbroncos.com?..."It is hard to see what the problem is from a picture so please disreguard any that do not apply to you."?


I'm kinda stuck with where else to shift this box so everything has clearance. One more....the front mount for the evap. box says to mount to the dash in the BC Broncos instruction sheet. With dash mounting, the piece would have to angle up and back to catch the dash. However, if I hold the front mount strip up, it just about makes it up to the cowl area. Is the correct front mount spot the cowl or the dash as the instructions indicate? My thought is that the cowl is a better mount since it is a straight vertical support vs. angled out to the dash.

Any other details on which hardware goes where for the overall A/C kit?

One more ? before I forget again....is there a way to manually open the heater valve to burp the air out of the heater core before wiring up the complete A/C system? I'm going to have the Bronco driving/running before I have the A/C system 100% complete.

You might lift the left side up a little. The strap should go to the cawl and that will hold the front up a little. You can hook up the heater valve and switch and just open the valve to burp it. The expansion valve can be rotated, be sure to use 2 wrenches.

mattt said:

Just mounted up the BC Broncos A/C Evaporator case in the Bronco tonight and I'm concerned about the Expansion Valve resting on the body/hump/firewall as shown in the pic. Anyone else with the BC A/C kit....is your expansion valve head resting on the body like mine is in the pic? If so, what sort of adjustments did you make so it's not resting on the hump/firewall area?

I'm assuming it should not be this way, but no matter which way I shift the evap case around, it's still resting on the hump/firewall sheet metal. It seems like over the long term this would break the expansion valve.

Suggestions? Thanks in advance.


One more....I received a few bags of hardware, bolts, nuts, screws, etc with the kit. Nothing in the instructions that I've found details what goes where and which hardware is to be used for which pieces. Is there a detail on this available?

Click to expand...

Definitely try all the suggestions above, but from your picture, notching your floor just a bit would be easy.

Get the hoses attached and I bet you still have a cm or 2 space to tuck at least the left/center side up higher

I'm getting ready to drop dime on this setup, would adding a 1" spacers on the mounting bolts help? Or will that push it out to far aft and into the dash or passenger seating area? In the second phot Matt took, It looks like this thing takes up alot of passenger foot room, or is it just layed down and not bolted in. anyone?

I had the same problem also. You should see how tight it is with insulation and carpet on the hump!;D I ended up drilling new holes in the firewall a little higher and a little towards the center. This gave me just enough room to keep the expansion valve from hitting. It did make the top air hoses a little tricky to get on but not too bad.

Also I don't think you can space it out a full inch from the firewall, maybe 1/2 inch but it's tight.

When I was designing the evap I used a low mileage EB with the insulation and carpet. Everything was tight but fit. The next EB we installed the evap into fit fine also. The EB's have not changed so I wil look to see if the evap have changed? Or maybe the expansion valve? I'll look.

You could probably space the case out from the firewall a bit, but I don't think 1" would work. Getting the spacers in there and keeping them in place while lining up with the holes in the firewall could be tricky. Yes, the evap box does take some pass. foot room, but not as much as it appears in the pic I have. That pic is taken from down below the pass. seat and shooting up. I took it that way so you could see the whole box in place. Broncos are a series of tradeoffs....you want A/C, your pass. is giving up some foot space.

I looked at rotating the exp. valve up, and it doesn't appear feasible because if you rotate it up(to clear the floor), it then will be in the way of the lower heater hose connection. Everything is packaged tight on the evap. case and changing one thing has an effect on everything else around it. I loosened the firewall bolts and shifted it up as far as it would go....exp. valve still resting on the floor/body. However, I did notice that once I install the rear mount up to the cowl it will actually pull the rear of the evap box up and probably lift the exp. valve off the floor/body. With the rear mount attached to the cowl with the flat stock, it pitches the box in a nose down-tail up configuration....meaning it's not on the same level plane as the firewall. I don't see an issue with that but figured I'd mention it in case it needs to be mounted totally level and square on the firewall.

Chuck, have you looked into if the box and/or expansion valve changed on V.A.'s part?

I started with the inner heater hoses tonight and realized something....does the heater valve go in the feed line to the heater core, or in the return line to the engine? If the feed for the heater is from the intake manifold and the return is to the water pump nipple then this pic shows the heater valve in the return line(the top line of the bulkhead fitting).

Shouldn't the heater valve be in the feed line to stop hot water from reaching the heater core when the heater is off? I don't know maybe it doesn't matter just that flow is interrupted??

Lastly...is the hardware sorting out something to just figure out? I already realized after looking at a few more bags of hardware that I used probable condensor hardware to mount the evap. box to the firewall. A little direction or labeled bags would go a long way. I can already see the next question...and I'm not there yet. Which A/C hose goes where? I just got a box of unlabeled hoses, and no info in the instruction sheets.

Moving this back up to rustle up some replies. My last reply above went long in the words.

So, to boil it down...with the evap box mounted in the Bronco, is it tilted up in the back with the rear mount(flat stock attached to cowl behind dash) in place?

Second...with respect to the heater lines, I pulled the pic above from a reply Chuck posted about 6 months ago in another thread. Does the heater shut off valve go before or after the heater core?

When using stock 5.0 heater tubes(which I am) across the lower intake the bottom tube comes from the intake and I believe is the supply for the heater. So, with the bottom tube being supply and coming thru the bulk head in the firewall, Chuck's pic shows the heater shut off valve after the heater core. It seems to reason that you would want the shut off valve before the heater core to stop hot water from entering the heater core with the heater OFF.
I realize you can just switch the hoses around on the firewall bulkhead, but to keep hoses from crossing over where they connect to the 5.0 heater tubes, the bottom hose has to be the supply line to the heater. And the pic shows the shut off valve in the upper line instead of the lower line. With hot water being allowed to the heater core when the heater is OFF would decrease the effectiveness of the A/C....right?

I'll take a look at mine tonight and see which line has the heater valve in it but I bet it doesn't really matter.

The box mold is mine so I don't think VA changed that. The core or exp. valve may have changed, A good point I will look into that. The drain must be the lowest point so water can drain but lifting the back up may be the reason some don't have the clearance problem. Also to use spacers you can use allthread studs in the box, put the spacers over the studs and stick the studs through the fire wall and use nuts and washers. We are working on adding a contents list for all our kits. The heater control valve was designed to be in the engine compartment (the reason for the long wires) in the hose coming from the intake. We like to put it inside to keep it out of the weather. When a temp control valve is off it still leaks so no matter which hose you put it in you will still get some hot water in the core. With this system the controler blends the hot and cold to control the temp anyway so it will work out the same no matter which hose you put the valve in.
The hoses are diff sizes so I don't think you can put them on wrong but if you find that you can the high pressure hose (smaller)goes to the expension valve

Thanks Justafordguy and Chuck for the continuing support. I didn't realize the heater valve was designed for engine compartment mounting.

I deferred to the pic I posted in this thread as I found it in another reply Chuck made in an older thread. I think it is better inside as well with the main reason being, there is very, very little room between a set of 5.0 heater tubes and the bulk head fittings on the firewall. Those hoses are at most 6" long between the two.
In regards to those hoses I found 1 pre-bent heater hose at Vatozone that can be cut in half and works perfectly to attach the bulkhead fittings to the 5.0 heater tubes. It's an "s" shaped hose with 2 90* bends. It's inexpensive too....under $10. That is the hose I used and it would be a tight fit getting the heater control valve in that same constricted area.
I'm going to flip flop from the posted pic and figure out how to get the valve in the feed hose inside to keep as much hot water out of the core as possible. I understand that it still leaks some thru, but my rationale is that on a long drive across the desert once all temps normalize and spread heat thru out the whole system that there could be additional heat bleed off into the core which may have an effect on A/C cooling.

Prior to buying the BC kit, I looked at VintageAir offerings on their site, and I figured the BC kit was made from the "Gen II Mini" shown there....maybe with different mounts but the same basic evap box design.

If-when you find out from VintageAir about the core and/or exp. valve having changed, please update this thread with the info. Thanks in advance.

The answer is right under our noses all along. It took my brother reading the fine print on the heater shut off valve to figure this one out. The valve needs to go before the heater core according to Vintage Air....see pic.

For anyone with the BC A/C & who has had insufficient cooling with their A/C, where is your heater shut off valve???

I also tried to blow thru the shut off valve to see how much leakage comes thru when it's closed....not one bit. It's shut tight.

mattt said:

I can already see the next question...and I'm not there yet. Which A/C hose goes where? I just got a box of unlabeled hoses, and no info in the instruction sheets.

Click to expand...

I found the instructions for which hose goes where......it was in with some VintageAir instruction sheets in the kit. I was looking in the BC instructions for hose diagrams mistakenly.

So figured out the hoses and a way to mount the heater shut off valve inside and on the bottom inlet line so it stops hot water flow before the heater core. It doesn't lay out as well as having the valve on top hose, but I think it will work Basically the heater valve bracket kinda lays over the top of the top heater return hose. You could also turn the heater valve pointing down, but I was trying to keep it as high as possible so it's not visible and won't be kicked by wandering feet.