Assuming your tank has the smaller (7mm ?) outlet.....

I doubt that having 2 filters is straining (strained) the pump.
Although the tank
shown likely has the larger outlet, P. 20.26 in Bentley shows both filters.

In spite of having installed all new parts at the time, the fuel pump on my '81
has always been noisy. It gets noisier on hot days, and/or at higher altitudes.
This may be due, in part, to a different issue (EVAP) than what you're
dealing with.

I've run that bus with only pre, then only post pump filter and IIRC,
with both. No real difference in pump noise level. The main issue IMO,
is the smaller sized tank outlet.
This aspect has been discussed many times here.

Neil.

On 3/18/15, Steven Shelton <shelton4@gmail.com> wrote:
> A little over four years ago I did the fuel filter “upgrade” on my 1.9L
> Westfalia.

> Last week while returning from a trip the pump really got loud. It even
> seemed like it was harder to get up hills. I'm replacing the pump but I
> wonder: by having two filters did I put too much strain on the pump and
> caused premature failure or is there something else I need to look at the
> prevent premature failure of the fuel pump?
>

-- 
Neil n

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