Date: Mon, 18 Apr 2005 19:44:28 -0400
Reply-To: Dennis Haynes <dhaynes@OPTONLINE.NET>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Dennis Haynes <dhaynes@OPTONLINE.NET>
Subject: Re: Bad has milleage
In-Reply-To: <20050418171711.45631.qmail@web80727.mail.yahoo.com>
Content-type: text/plain; charset=US-ASCII
It is possible for either the transmission or the torque converter to
slip. A bad torque conveter may allow a slight slip. A slipping trans
will usually be more load sensitive and obvious. If the trans is
slipping, the clutches will soon burn out. A defective torque converter
can go on forever or until the excess heat messes up the engine cooling.
If new pads appeared to be tight, the calipers are shot. Usually, rust
or corrosion builds up in the cavity while the piston is extending due
to pad wear. When you push the piston back, it binds on this gunk. Even
if it does not appear that bad, after things heat up, a constant drag is
there. New pads should not be any tighter than old pads. In reality, a
proper brake job really includes caliper and wheel cylinder replacement.
Hoses should also be checked carefully but they can fail internally so
they should probably be changed at least once in 10 years. Yes, Vanagon
calipers do seem to last a long time but there is a risk there. Regular
brake fluid changes do help extend their life. I like to flush the
system out before replacing pads if the calipers are to be re-used.
Dennis
-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf
Of Leo Lee
Sent: Monday, April 18, 2005 1:17 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Re: Bad has milleage
Thanks Dennis, the two new tires are exactly the same as the rears,
Capitol R185/R14 8ply, but the rears are about 10,000 miles old. The AC
was off, it is automatic. I have recently replaced both of brake discs
and put new OEM pads on both front wheels. A little tight for the first
few miles but should not be a big drag like that. I have not checked the
O2 sensor, will look into this. What do you think about the possibility
of a transmission slip? I put RedLine ATF in there about two years ago.
Leo
Dennis Haynes <dhaynes@OPTONLINE.NET> wrote:
Are the new front tires larger than th the rears? Th heads did not
change the RPM to speed ratio. Are you packing stuff on the roof or
using the AC? Maybe you have a brake that is dragging. Is this an
automatic or 4 speed. An automatic with the AC on and stuff on the roof
will not do any better at 70 mph. Just because the O2 sensor is new does
not mean it is good. Test it to make sure it is working properly. That
may explain the poor hi sped performance.
Dennis
----- Original Message -----
From: Leo Lee
Date: Monday, April 18, 2005 8:16 am
Subject: Bad has milleage
> After the head job, the gas consumption increased to 15-16.5 mpg
> in three camping trips. The compression is good, spark plugs,
> rotor, timing, air cleaner, wire connection, vacuum are all fine.
> I also took the catalytic converter out and found the ceramic
> materials inside are clean and in excellent condition, the O2
> sensor was replace about 6,500 miles ago and still nicely in
> place, connection no problem. On the freeway, I notice the rpm at
> 65 mph is about 3,900, at 70 mph is way over 4,000. I remember
> before the head rebult, the rpm was 3,800 at 65 mph, and slightly
> over 4,000 rpm at 70 mph. I wonder what is this mean? I put 2 new
> tires at the front, would that be the reason for that? The
> multivan drive well, smooth, but doesn't seem to perform well at
> higher speed. The gas mileage for the first tank of gas after
> rebuild was 15.3 mpg, the second tank was 16.5. Is it necessary
> for the engine to break-in after the head replacement? I used two
> new AMC heads from BusDepot, and replaced
> all 8 hydraulic lifters.
>
> Leo, 1991 multivan
>
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