All
For those that have follwed this project, and those who consider fitting a Dual Servo in the future, I would like to now share some background information on this project.
In the original batch of 21 servos we ordered from MBM, 4 members chose the Zinc servo (14 chose Powder Coated, and 3 Chrome).
Peter Edwards was the first to fit his Zinc servo to his road going Sportster, and reported an issue with sticking brakes almost immediately. After quite a lot of discussion in the back ground, and conducting various tests, our conclusion was that there was a fault with his servo.
The three other members were contacted, and asked to carefully test their servos: Robin Martin reported back that he too had the same issue. The other two members, with part built kits, were then asked to test their servos using their daily drivers to provide the vacuum, and we believe they too are experiencing the same issue.
Before other Dual Servo adopters start to worry, the Powder Coated servos are made by a different manufacturer and are different from the Zinc servos. We have tested several of the Powder coated servos, and the Chrome servos, for the same issue, and none have shown any signs of the problem. It appears to be a batch fault with just the 4 off Zinc servos we received from MBM.
(Rob Nicol - you should not be affected as your Zinc servo was the original supplied to me from Duksville UK, and may even be from a different manufacturer)
We contated MBM, as soon as the first two road going zinc servos seemed to be causing problems, and they agreed to replace them without quibble.
When our later tests suggested the final two zinc servos had the same issue, we sent Peter's back to MBM for their comments: their initial report is that there is not a fault. However, we feel they have not tested it thoroughly and seemed to have missed the point a little. I am currently pushing them to carry out further tests to replicate our issue.
Steve Brown at MBM has been very good about all of this: despite finding no fault with Peter's unit, they have now agreed to replace all 4 zinc servos (we have paid to upgrade them to the Powder coated specification). I am now in the process of trying to get MBM to send just two Powder Coated Servos sent separately to the UK, but do appreciate freight works out very expensive for small quantities.
The second batch of 24 servos were all Powder Coated (for reasons which are now obvious, and that it standardised the adaptor plate) so we do not anticipate any further issues.
We now have 40 Powder Coated, 3 Chrome, and 1 Duksville Zinc servos distributed.
So, what can we draw from this experience?
I think MBM have been very good in their dealings with us - and would recommend them to anyone who wants to approach them direct for future orders.
And for any potential users,
choose a Powder Coated servo!
