Eberspacher BA6 Tear down, restoration, and installation

[RONIN10]

I've been fairly neglectful of the Samba over the past year or more, really only contributing to the Seattle threads and not much elsewhere. I continue to read, digest, and learn, but really wanted to add something. Of course, the BA6 has been covered to a great extent already, and I'm certainly not the expert on them, but hopefully this thread won't be redundant rather shed some additional light on - maybe - some darker corners of a BA6 restoration.

So with all the introductory nonsense out of the way, let's dive into the particulars. First, my bus was never equipped with a BA6, BN4 or any other aftermarket gas heater so this will be a complete add-on. I sourced two complete systems over the past couple years, one from a junkyard in B.C., Canada, another from Ken @ The Bus Co. These are in various states of decline, but hopefully I'll be able to cobble together a single, well-functioning system between them.

Prior to starting this thread, I did some component level testing and attempted to bench test one of the systems. I chose this system (System A) because the other (System B) dropped a massive pile of rusty innards out of it when tipped on end. The harness was in good condition as well, so System A became the primary, System B the spare.

After individually testing most of the components on System A and finding they were working well, I decided to do a full bench operation test. Unfortunately, the fuel pump wasn't getting any power so I had to dig a little deeper. Power for the fuel pump is relayed to it via a set of points integrated into the combustion chamber mixing motor. Unfortunately, the mixing motor is currently seized to the heater core where it remains stuck today, the junction between the two bathing in nightly doses of PB blaster and being treated to screwdriver to scrapings to clear the crud in the seam.

Fortunately, System B's combustion chamber motor bench tested fine so I really just need to swap out the heather cores. That's going to generate a bit of work since both innards have some unpleasantness. I drilled out the rivets on each System and here's the situation...

System A, Upper Shell:

Not bad at all, though the hanger bracket on the right hand side in top photo has a couple of the spot welds separated.

System A, Bottom Shell:

It looks like someone used it for target practice and that baffle is completely shot.

System A, Heater Core (with seized combustion motor):

My trigger happy predecessor killed the heater core too. The holes didn't seem to penetrate the upper surface so I suppose I could probably weld up the holes and make it functional again (if I can get the combustion motor removed).

System B, Upper Shell:

Looking pretty good, I'll probably use this one in my system. There is some rust deterioration on the left hand inner surface, but it's not bad at all, still a lot of material left. This one had a rodent nest in it at that spot so the rust is fairly localized.

System B, Bottom Shell:

Some problems here as well, but mostly minor. The baffle plate needs to be replaced altogether or at least the left-most section repaired. There's also a hole about the size of a quarter at the right where it's rusted through. That's another patch.

System B, Heater Core:

Looking good.

So System B wins as the heat exchanger to be restored for my bus, while the wiring, fuel pump, relays, etc. will come from the System A. More to come later.
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Andrew

Oscar: 1976 Westfalia Deluxe Camper, 2.0L FI, Manual Transaxle

[RONIN10]

The last few nights, I've been focused on the combustion chamber blower motor and the associated points for the fuel pump and the glow/spark plug. I started with the System B blower motor while the PB Blaster soaked into the seam between the blower motor and the heater core on System A.

These blower motors are pretty simple to disassemble for a cleaning and a bench test. To start, the mixing fan is held onto the shaft with a set screw. Align the set screw with the hole in the housing and use a 5/32" Allen wrench to remove it. If you have the kind of allen wrenches with a ball on the long end, you'll likely slip the wrench in the set screw. Make sure have one that finishes with a squared off end. You can see the hole in the housing here:

It might be a little sticky, but you should be able to work the fan off gently. The fan is cast from a fragile material - magnesium I'd guess - so if you resort to prying, do so very gently. I found a tip of one of the blades was clipped away on my unit and later verified that this was the case on my other unit as well, so i think this is intentional and is likely done to dynamically balance the fan. Here's what it looked like on the two fans I have in my possession:

Next, turn over the combustion fan and carefully remove the rubber boot. Pay particular attention to not put too much side load on the wiring plug as the plastic plug simply presses into the blower motor housing. If that plastic is brittle, it'll break easily. Depending on the life your heater has previously lived, the boot can be in a various states of decay. System B's boot was supple and in good order and will be reused, System A shows multiple symptoms of being tampered with including it's boot which had a tear around the wiring plug.

Once you remove the boot, you'll find a snap ring underneath. Pry one of the ends out from the slot it rests in and work your way around the circumference of the blower motor until the whole ring is loose. You should now be able to remove the motor core from the motor housing and will end up with a silver capsule with a rubber donut around the middle (for vibration isolation):

Remove the rubber ring on the end with shaft protruding from it. Under that ring is a slotted screw. Remove that and lift off the silver cap and you'll be able to see the points for the fuel pump:

Powering the motor rotates the shaft and the worm gear with it which meshes with the plastic cog. The shaft of the plastic cog is non-circular so when the protruding portion is facing down in the above photo, it pushed the points open and the fuel pump loses power momentarily. To clean this area up, I took a little 320 grit sandpaper and ran it back and forth between the points few times, then took a cotton swab wet with carb cleaner and wiped around whatever I could get access to. The plastic cog, got a spritz of white lithium grease and I replaced the cover.

The other side has a similar silver cap that needs to be removed and you'll find the points which operate the spark/glow plug.

Same process as before with the sand paper and cotton swab, but no lithium grease this time. Instead, I dripped a few bits of engine oil onto the felt pad that runs along the motor shaft. Replaced the cap and the silver capsule is complete again:

To bench test the motor, connect your negative lead (black in the photo below) and red lead from a 12V source as shown:

Not the best photo, but it was the only way I could get the motor to not roll around when applying power. To put it in words, place the motor with the long shaft to the right. Rotate the motor until the plug is facing you, Within the round plastic plug, you'll see four pins arranged in a square. The lower right hand one is your positive power, the lower left is your ground, the upper left is the power signal out to the fuel pump, and the upper right is the power signal out to spark plug. It's pretty cramped in there, especially if you're using alligator clips, so be careful to not touch your leads.

With power applied to the motor and if you've left off the caps off either end, you'll see the fuel pump points working fairly slowly and the spark plug points will be a blur, they're moving so fast. If you want to verify the points are working, you can use a test light between the positive terminal on the battery and the upper left or right pins. Like the action of the points, you'll see the test light flicker slowly for the fuel pump circuit and will appear on constantly (due to the rapid points movement) for the spark plug circuit.

Doing these test, the motor from System B checked out okay. I'll take a look at System A's recently freed motor tomorrow, but I expect to find an issue as it wasn't powering during my attempted full-up bench test.

So this is just a repeat of the photo at the top of the page, but all finished and cleaned up, it'll look like this:

I almost painted the housing, but decided to put my time elsewhere. The material is in good condition and no one is going to see this anyway.

BTW, if you guys are not following notchboy's videos on YouTube or heater threads here on the Samba, you really should be. He's the resident expert when it comes to the BA6s and BN4s. I'm just documenting my process for posterity, but using a lot of the information he has provided me.
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Andrew

Oscar: 1976 Westfalia Deluxe Camper, 2.0L FI, Manual Transaxle

[Xevin]

Nice job buddy
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Keep on Busin'

[RONIN10]

I've made some progress over the last week or so on restoring the shell of the BA6. After wire wheeling the heck out of the shell, I used the bullet-shot piece from my spare system as a donor and cut a patch for the rusted through section. Bleyseng did me a favor and welded in the patch for me, though I hadn't trimmed out the thin metal sufficiently so he couldn't weld it fully closed:

After some grinding:

I used some JB Weld to fill in the gap and sanded it down relatively smooth:

If I had to do again, I would have used the Devon metal patch I used to elsewhere on the shell to fill some pinholes. I'm not certain how well the JB Weld will hold up to the heat. Now sealed up, I generously bathed both shell pieces in Ospho to encapsulate the rust from spreading and then painted the shells.

I used the following in my paint process:

The paint prep is awesome stuff, I use it as my last step prior to powdercoating everything and it makes a tremendous difference in adhesion there and will here as well. The high temp primer and paint was leftover stuff I had sitting on the shelf. We'll see how it stands up to this environment. Though I'm more concerned about the long term durability of the paint than temp resistance since this is mounted under the bus.

Overall, I didn't worry too much about appearance, but did make a limited effort to getting things looking good. Had I been more concerned, I'd have added some Devon metal patch to the pitted areas and smoothed and sanded them to a nicer finished. All said and done, you can still see some pitting upon close inspection, not sure how well it shows in the pictures. Anywhere, here's the finished shell:

There some additional pics in my gallery if you're interested.

Cheers.

Andrew
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Andrew

Oscar: 1976 Westfalia Deluxe Camper, 2.0L FI, Manual Transaxle

[Bleyseng]

Looks great and it's time I did the same to mine!
_________________
70 Ghia Black convert-9/69 build date-stock w/133k 1600 SP-barn find now with a rebuilt tranny and engine
77 Westy 2.0L w/Ljet, Camper Special engine-95hp and with LSD!(sold)
76 Porsche 914 2.1L L20c, 120hp Djet (sold)
87 Syncro Westy Titan Red 2.1L 2 knob 100k miles

[notchboy]

Keep going. Im particularly interested in the return air routing
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[Stuartzickefoose]

I got two extra full setups if one of you needs parts let me know and we can make it happen.
_________________
Stuart Zickefoose

2011 Jetta Sportwagen TDi 6 speed manual

206-841-7324
[email protected]

[RONIN10]

Some reassembly:

The rivets posed some issues. The original ones were - more or less - tiny grommets. I had plenty of pop rivets on hand, but they weren't the correct diameter, you need 5/32" (4 mm) rivets.

So attempt number 1 was to use my 1/8" rivets. I riveted the whole thing together, flipped it over and...several rivets fell out directly while many others were easily pushed out. Went to the local Tacoma Screw the next day to get the correct size rivets. They had several varieties of 5/32" rivets with different grip ranges, but were out of aluminum rivets with the smallest grip range (1/8" by the way) so I ended up buying the stainless steel ones which were in stock. The problem here was that when I attempted to rivet these ones in - due to the lack of ductility of stainless steel - they would snap before they compressed down fully onto the sheet metal. So the next day went to the local home improvement center, found a 5/32" aluminum rivets and all was well, at last.

After this, I had noted some scratches on the surface from handling so my paint job seemed a little thin. I scuffed the existing paint and hit it with several more coats of paint. We'll see how that holds up over rest of the assembly and test process.
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Andrew

Oscar: 1976 Westfalia Deluxe Camper, 2.0L FI, Manual Transaxle

[RONIN10]

Quickie update...this project hasn't died, just been pushed back by work and buying this bus.

I have attempted a few bench tests, but I'm not getting any power to the fuel pump. I have verified that I can manually actuate the fuel pump and it will pump fuel so I need to back up a bit to the points in the combustion fan and make sure they're fully opening and closing correctly.

I'm out of town for a bit with work so I'll be update on the points situation somewhere around the 4th of July weekend.
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Andrew

Oscar: 1976 Westfalia Deluxe Camper, 2.0L FI, Manual Transaxle

[vwwestyman]

I'm watching. I've got a setup I may install in the '73. I just need to find the flapper box that the return air blows into. And maybe the front air duct that the heat sensor is placed in.

(Anyone have either one, or both?)
_________________
Dave Cook

President, Wild Westerner Club

1978 Champagne Edition Westy, repowered to '97 Jetta TDI
1973 Wild Westerner
My Thing

[RONIN10]

[RONIN10]

Well, I managed to get the BA6 working.


Link


Link


I verified that the points were working in the old combustion fan, but something in there is hosed up as the voltage to the fuel pump was too little to actuate it. I had spare innards for the combustion fan so I swapped that in to the combustion fan housing and voila! it fired up. It backfired once, burned off some crud and worked great from there.

I have some challenges to get it to mount into the vehicle as the BA6 wasn't meant for the '76 buses, only the later years...the hanging brackets are missing and the holes for the belly pan are just holes, not threaded for screws.

Anyway, progress at least.
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Andrew

Oscar: 1976 Westfalia Deluxe Camper, 2.0L FI, Manual Transaxle

[Bleyseng]

Nice work! Now to get in installed before winter.

I have to get going on restoring my BA6....
_________________
70 Ghia Black convert-9/69 build date-stock w/133k 1600 SP-barn find now with a rebuilt tranny and engine
77 Westy 2.0L w/Ljet, Camper Special engine-95hp and with LSD!(sold)
76 Porsche 914 2.1L L20c, 120hp Djet (sold)
87 Syncro Westy Titan Red 2.1L 2 knob 100k miles

[foxmon]

Thank you Andrew, very helpful, and nice job!

I got going on mine today. I figure if it's plumbed under there it ought to run, again. It did 10 years ago...

I'm stuck removing the combustion air blower. Clamp is off. It looks like there is a (asbestos?) gasket in there glueing things together?

I read

[cmonSTART]

Drill the rivets and.split the heater's outer housing apart. The blower should come right out,
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'78 Bus 2.0FI
de K1IGS

[busdaddy]

The combustion blower should come out by removing the clamp, no rivet drilling or shell splitting required. They do stick to the seal aggressively sometimes, a few good sideways whacks with a deadblow hammer and/or some prying at the joint should do it, don't chew up the flanges or seal.
Mark both parts so you can line them up the same way when it goes back in.
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Rust NEVER sleeps and stock never goes out of style.

Please don't PM technical questions, ask your problem in public so everyone can play along. If you think it's too stupid post it here
Stop dead photo links! Post your photos to The Samba Gallery!

Слава Україні!

[cmonSTART]

[vwwestyman]

I got started on trying to get mine to run last night.

The furthest I got was getting the two fans to turn on with it on my floor.

I had disassembled the combustion fan as described and put it all back together but the fuel pump wasn't clicking.

Disconnected it and tested with battery charger. The connection will spark when I tap it with the charger lead, but that is it. It is frozen up.

I pulled the ends off and filled it with carb cleaner, so hopefully overnight that'll have loosened things up.

There isn't an adjustment with the pump at all, is there? The one end screws into the body and is held in place with a lock nut. I'm just hoping that isn't a mechanism to adjust the fuel output or something...
_________________
Dave Cook

President, Wild Westerner Club

1978 Champagne Edition Westy, repowered to '97 Jetta TDI
1973 Wild Westerner
My Thing

[busdaddy]

[vwwestyman]

Dammit! Ha ha, after I took it off, I thought I had read that was the case. Didn't remember before... Oh well. There appears to be some kind of push rod in there which was gummed up. So probably for the best.
_________________
Dave Cook

President, Wild Westerner Club

1978 Champagne Edition Westy, repowered to '97 Jetta TDI
1973 Wild Westerner
My Thing