Changing dometic VT 2500 toilet seals

Submitted: Thursday, Jun 20, 2013 at 22:36
ThreadID: 128795 Views:8300 Replies:8 FollowUps:2
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Hi BOG ers
The water in the bowl of our toilet was disappearing. Purchased the seal and ball kit from caravans plus, but without instructions.
Have contacted Dometic for advice, but have not yet got back to me, and cannot find anything on line for this particular model.
Can anyone offer some advice??
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Reply By: Quicksilver - Friday, Jun 21, 2013 at 03:55

Friday, Jun 21, 2013 at 03:55
HI Ian,

On internet "spare parts diagram-DometicVT2500"
See diagram of all parts.
When removing items 5&6 only take out two screws as third screw is for item 8 and must not be removed [it is spring loaded] if 3rd screw is removed you will need to purchase item 8 at a cost of over $100.00

Quicksilver - Breakin Loose

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AnswerID: 586022

Reply By: sharon&ian - Friday, Jun 21, 2013 at 04:09

Friday, Jun 21, 2013 at 04:09
Too late David
The third screw has been removed and wondering where to go to next. Worked this out for ourselves too late...
Your post has been a great help and will follow up.
Trying to work on the spring and putting in this in place before we source a $100 new one.
Lots of colourful language happening in the van department.....
AnswerID: 586023

Follow Up By: sharon&ian - Friday, Jun 21, 2013 at 04:13

Friday, Jun 21, 2013 at 04:13
Is the $100 for a tool to complete the job
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Reply By: sharon&ian - Monday, Jun 24, 2013 at 00:33

Monday, Jun 24, 2013 at 00:33
$97.13 for the part delivered if we had waited before trying to fix this.
Have learnt a valuable lesson to be patient and wait for replies on this forum..
AnswerID: 586024

Reply By: Quicksilver - Monday, Jun 24, 2013 at 03:28

Monday, Jun 24, 2013 at 03:28
HI Ian,

Sorry mate fell for it myself. You would think there would be notification from the manufacturer not to do this, I used to make money in my business the fair way.

Best Regards.
Quicksilver - Breakin Loose

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AnswerID: 586025

Reply By: wylaway - Sunday, Jun 30, 2013 at 03:00

Sunday, Jun 30, 2013 at 03:00
Hi All

Same system, different problem.

I have a Dometic VT 2500 vacuum flush toilet in my 2007 BT. I am afraid it has not fared well on the Gibb River Road. Often, it will not hold a vacuum for a reasonable time period and will re-pressurise after 2 hours, or 1 hour, 20 minutes or when it is very bad, 1 minute until you need the toilet. Annoying, but this can be managed by turning the pumps off or removing the toilet cassette. Much more serious is that at present the system will not pressurize and create the vacuum. Therefore, we cannot flush the toilet and consequently cannot use the toilet. Motor works well and constantly runs trying to create the vacuum. All the pipe joints are fine. Problem would appear to be in the vacuum/base station.

Before I pull out the base station, are there any do and don’t when pulling apart these units and any suggestions where to start my investigation. Probably something has shaken loose on GRR.

Any advice welcomed.


AnswerID: 586026

Follow Up By: Bobrovin - Sunday, Jun 30, 2013 at 03:38

Sunday, Jun 30, 2013 at 03:38
To make sure the pump is pumping, take out the cassette and put your finger over the hole in the 13mm spigot and push in the red switch. pump should start and stop in a matter of seconds. If this is OK than its either the O rings not sealing or the cap leaking.
First thing to check is the "O" rings, the small 13mm one and the double one. make sure they are cleaned at regular intervals as well. Also check that the cassette is going all the way in over these rings.
Push the sliding parts of the cassette in and make sure the inside surfaces where the O rings seal are clean. sometimes a buildup can form on the suface
The cap could also be the problem. check that the seal inside the cap is intact.

All the "O" rings in the system except the double can be purchased at CBC bearings or similar for about $2 ea instead of the $13 odd that dometic want for them
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Reply By: wylaway - Monday, Jul 01, 2013 at 08:06

Monday, Jul 01, 2013 at 08:06
Thanks Bod

In Kununurra now (in a caravan park with working toilets) doing a couple of tours and will attempt to fix in a day or two. Will follow your suggestions and let you know the outcome.


AnswerID: 586027

Reply By: wylaway - Friday, Jul 05, 2013 at 08:58

Friday, Jul 05, 2013 at 08:58

Just a quick update as promised. Problem was not seals but one of the plastic components. For those familiar with the VT 2500, there is an inverted cone shaped plastic tube in the base unit from the diaphragm up to a unit which appears to measure if the vacuum is reached. The thin end of the tube has snapped and had to be reconnected. I have “jerry rigged” the connection by using some 12mm clear plastic tube with a couple of hose clamps to re-establish the vacuum but I will have to re-order the correct part from Dometic when we re-turn to Melbourne.

Obviously, cleaned and re-installed all o-rings.

Thanks for advice and suggestions.

AnswerID: 586028

Reply By: sharon&ian - Friday, Jul 05, 2013 at 17:11

Friday, Jul 05, 2013 at 17:11
This has been all interesting reading
Thanks everyone
Another tip we practise is the care of the o-rings.
We keep them lubricated with silicone spray at regular intervals to prolong their life and make our life easier.
The whole concept of this system is good, however a pity there was no follow through for the long term product.
I still have not heard from dometic service regarding information sought in the first instance.

Ian & Sharon

AnswerID: 586029

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