lDN: the first Alx400 B7 d/d

This is the first alx400 bodied volvo B7TL d/d to see service in London [London United examples closely followed]. the production of the Volvo B7TL has now finished - at least for the London area, as all new buses delivered to London after 1/0ct must comply with Euro4 emission standards.

Regards

Yoram

In the October issue of BUSES Magazine, a reader was complained about B7s making so much noice and this has to be resolve urgently.

The ones we have at Lawrence Hill are Mk1 B7TL with the numerous air and hydraulic problems Volvo's excuse for no kickdown on the very first B7TL's was that due to the computer control on both the engine and gearbox it wasn't needed.  How wrong
could they be.

The B7s problem is likely to be the cooling fan motor which is hydraulic and has a built in temperature sensor for the London case.  The sensor fails causing the fan to run at max speed even when cold hence the noise.  32014 definitely has this fault.

I have asked staff at First Bristol and they said the replacement part cost an arm and a leg so operators do tend to run buses with fan motor faults for as long as they dare.

原帖由 norrislaw 於 2006-10-10 08:02 發表
The B7s problem is likely to be the cooling fan motor which is hydraulic and has a built in temperature sensor for the London case.  The sensor fails causing the fan to run at max speed even when cold hence the noise.  32014 definitely has this fault.

I have asked staff at First Bristol and they said the replacement part cost an arm and a leg so operators do tend to run buses with fan motor faults for as long as they dare.

This is a common problem of B7TL. I have come across these noisy B7s for thousands of times.

Volvo certainly needs to sort out this problem.

The volvo B7 d/ds are certainly noisy, and bad maintanace by the operator [and First Bristol certainly does not have a good record] makes it worse!

regards

Yoram.

I think it is one of the reason makes operators not to buy B7s and switch to Trident and DB250LF or Omnidekka. I noticed even on the latest batch of Gemini B7s, the noise problem still exists after a period of time.

原帖由 norrislaw 於 2006-10-10 20:35 發表
I think it is one of the reason makes operators not to buy B7s and switch to Trident and DB250LF or Omnidekka. I noticed even on the latest batch of Gemini B7s, the noise problem still exists aft ...

Well actually there hasn't been a lot of switching around over the time - All the models have their
loyal customers. The Tridents are more thirsty, and not as reliable and easy to maintain as ADL
claimed, but it's still a good bus, so readily avialable, and it is "British". The B7TL is reliable, more
fuel efficient, but lost a lot of customer as a result of it's late entry to the market. The DB250LF
was hardly a serious contender because of its obsolete design, but it is fuel efficient and reliable.
The N94UD was a fuel efficient and reliable design, and in fact the chassis that suffered to the
N94UD was, guess what, the Trident.

Thing is the cooling fan problem of the B7s are not something most operators care about - because
it does not cripple their buses to get into service anyway, apart from sounding a bit dodgy. It does
plague every Volvo, not just the B7TL. But it becomes much more obvious on the B7TL because when
running normally, it is one quiet bus.

Well the B12M which First Devon & Cornwall operates on NatEx 336 definitely have this noise matter, I understood this problem will not causing any danger or harm to anyone but it is not environmentally friendly and sustainable.

I would quite like to know about the DB250LF, if anyone has the time please kindly open a new post to discuss about this type.