Webasto WP1021

[Moi427]

My apologies for not speaking Swedish being Dutch, but I will try in English if that's OK. 
By the way, I introduced myself shortly in my profile. 
I have a TGB C304 1314 ambulance and have a problem with the Webasto WP1021 parking heater in the ambulanceunit 

Two questions: does anyone have documentation for this Webasto WP1021 parking heater since I can't find it anywhere? 
I would like to know how to repair it as there is a leak that seems to be at the waterpump at the bottom right if you look inside standing next to the box. 

The second question: I bought a spare WP1021 that looks like almost new (function not tested), but it turns out to be 12V instead of the current 24V: my mistake since I only saw "WP1021" and was happy. 
Does anyone have experience with how to use this 12V version in our 24V system, is that possible with likewise an inverter 24V > 12V?

 

Thank you!

Jan de Vries

[Ron]

Hello Jan,

Welcome @ Terrangbil.net.

I have no info/documentation on the Webasto other then the usermanual, servicehandbook and sparepartslist for 12 and 24 volt.

Find it here on the downloads page of this forum; https://terrangbil.net/forum/index.php?/files/file/37-webasto-wp-1021-12-och-24-volt/

It is in swedish but it might help. Otherwise, i speak swedish so feel free to ask when some translation is needed.

 

About the 12/24 volt question, you can run a converter but these heaters use very little power. Some people connect stuff like this on 1 batterie and in such way have a 12 volt feed. if you have good batteries this should not be a problem. I would however advice to rotate the batteries once every while when you do this..

 

[Moi427]

Hello Ron (if I found your name correct),

 

Thanks a huge lot, that's a great document that will help me definitely!!

I'm going to translate it in Dutch, like I also did with some other documents: Google helps me with that.

So I'm really happy you provided me with this manual/document, that makes trying to find the cause hopefully lighter.

Of course, the challenge of getting the Webasto out of the TGB remains, how difficult it is to reach...
But that seems (to me at least) a standard part of tinkering with the TGB.

So once again: thanks a lot with that link!

 

[Ron]

Good luck with it.

Yes, working on a TGB is not always easy. Most parts are a bit hard to reach but the good thing is that you can skip yoga classes!

[Moi427]

That's entirely true...!

In the service manual of the WP1021, the 24V water pump is indicated as number 368.865. I also find the designation U4808 on the web, but I can't find that number in that servicehandbook. 
Is it known whether this is an alternative number for this water pump? 
I also see it on the Webasto type plate of water pumps that are sold as the same number 368.865, while there's also a green Bosch type plate on it.
It is (for me) a bit confusing.

I don't know (yet) whether and which number is on my pump, I haven't been able to dismantle the heater yet. 
However, the cause of the leakage is now 100% clear from testing: the shaft seal is broken.

[Ron]

Unfortunatly i do not know a lot about those numbers but it seems to me that 368.865 was de partno. that Volvo used for it while for example Bosch produced them and used a different  Bosch partno. This is very common practice.

Seals however, often can be simply measured and found on the internet. I hope this will be the case for your shaftseal.

 

[Moi427]

That common practice is correct. I've had contact with different companies and persons, up until now nobody knows about the numbers but I've the same feeling. One person told me the pump I have probably is the first type Webasto used and the second type thereafter (he sells only 12V and also tests and repairs WP1021's as business) is the second type.  The shaft seals according to him is hard to find. 

Anyway, I also asked someone for measures of length and diameter: if that's ok for a U4808 it should have to fit. 

First I need to gather courage to get the WP1021 out of it's housing...:-)

[Ron]

Let us know if you get it fixed, there must be more people interested in this !

Good luck,

Ron

[Moi427]

I will Ron, thanks for your comments.

Cheers, Jan

[jim molloy]

Jan, 

You are fortunate as many of the TGB1t314 trucks never had the Webasto heater unit installed. Mine was one that was plumbed for the heater but no heater installed. I chose to install a later model 24v diesel Webasto Thermo Pro 50 Eco and it has served my very well. If you have a "new" WP1021 in 12v, I suggest you replace the old unit with the newer one and simply add a 24v-to-12v converter.

 

I must strongly disagree with Ron's comment about being able to skip yoga classes. If you are already practicing, keep it up.  I have driven and repaired Volvo TGB trucks for over two decades and have been a yoga instructor since late 2014. Practicing yoga on a daily basis (often two practices/day) has brought me better balance, better core strength, better flexibility, greater relaxation and less frustration, greater focus and the loss of 30 unnecessary pounds. This year will be the 26th year of my wife and I hosting Northwest MogFest on our family farm in rural NW Oregon. I was founded to gather owners and others interested in high mobility European vehicles. Since 2014, we have offered daily yoga practices and attendance is quite healthy.

 

Best wishes for a quick resolution to your heater issue.

 

Jim Molloy

Waldersee Farm

1975 TGB1314A "MAMMUT"

 

 

 

 

 

[Moi427]

Hi Jim,

Thanks for your very nice comment! Ron's comment was of course humor, I do believe people have much help from yoga although I myself do other exercises. Keeping moving is really important.

 

Your diesel Webasto is a nice addition, well done! And yes I'm happy the heater is in there, although not (yet) working. There's a chance I find a good 24V waterpump or get the old leaking one repaired, but otherwise I probably will use a converter for the 12V waterpump.
When I would replace the entire heater for that NOS 12V WP1021, I guess it's the simplest to have the 24V>12V convertor directly before of the control unit, so that only 12V goes to the heater?
At this moment I need to remove the heater from the cabinet and must figure out how to do that at best, since it's quite tricky for the lack of space.
I see 4 bolts where the heater-frame seems to be attached to the backpanel, I presume these bolts turn into nuts welded on the back of that panel or thread anyway. Maybe you still can remember this?

 

I looked up your Northwest MogFest: what a great event and so many years already! A little bit too far away, that's a realpitty. Also having someone in the neighbourhood who can repair these TGB's when needed would be great, places for that aren't easy to find. Also found a picture your TGB 1314, nice! Also that Moonshade is clever. 

Well, if someone over there would like to own a 1977 TGB 1314 they always can contact me 🙂

 

Have a lot of fun over there!
Jan de Vries

[Moi427]

I bought the second version of the 24V pump, the U4808. Quite a bit smaller but the same capacity and diameter of fluid lines.

It appeared to be simple to remove only the old pump (the W368 865), fortunately. The easiest way after that was cutting the wires, remove it and make a new connection with the new pump.

I had to run the engine to fill the cooling system of the ambulance unit and get the air out, so that heated the system already, but the heater did run without any leaks. Tomorrow I'll test it in the morning when colder and only running the pump, so hopefully that will heat the cooling system as it should be.

For now I'm very glad I didn't have to get the entire WP1021 out and this new (NOS) pump runs properly!