J.Sweet: question on 92 Volvo 740

[geronimo]

Re: the water temp gauge issue: You were right. The gauge on my
740 turbo is just designed to stay at mid-scale as long as there is
not a problem with temp. I disabled the fan, and let it heat up above
normal a bit, checkng carefully with an IR temp gun. Sure enough when
it got to 215 deg. or so, then it started climbing towards the red.
So it is really working OK.
2nd....I still have a lot more brake pedal travel than I would
like...but then the 740 sedan I used to have also had a lot of brake
pedal travel, too...always did. So I was hoping you can give me an
idea of how much pedal travel your 740s take to begin the grab. I
recently changed brake pads on front, although none of the pads were
really worn out, then bled the brakes a lot, and the travel is about
the same before and after...quite a *lot* of travel. They don't feel
mushy when you step on brake, its just a matter of a lot of travel
before they begin to grab. Since it has ABS, with I think four lines
going to the controller on the left shock tower, could air in those
lines also mess up braking? Since they don't have any bleeder
provision like the brake lines I am assuming not, but I wonder.

Also I asked about the voltage drop I was getting across a
dual-diode- type battery isolator I installed. I have now learned that
there is no way to get around having the voltage reduced about .8
volts or so with this "passive component" type isolator. So since I
can't tweak up the alternator votage a bit, I will not be able to
fully top off either the car battery or the camper battery with this
device. The solution is to install an "active" type isolator which
uses series pass transistors, and they have virtually zero votage
drop. The drawback is they are about three times the price.

Thanks, Geronimo

 

[James Sweet]

2nd....I still have a lot more brake pedal travel than I would
like...but then the 740 sedan I used to have also had a lot of brake
pedal travel, too...always did. So I was hoping you can give me an
idea of how much pedal travel your 740s take to begin the grab. I
recently changed brake pads on front, although none of the pads were
really worn out, then bled the brakes a lot, and the travel is about
the same before and after...quite a *lot* of travel. They don't feel
mushy when you step on brake, its just a matter of a lot of travel
before they begin to grab. Since it has ABS, with I think four lines
going to the controller on the left shock tower, could air in those
lines also mess up braking? Since they don't have any bleeder
provision like the brake lines I am assuming not, but I wonder.

I don't have the car near me at the moment but it does have more pedal
travel than my 240, and the brakes do not feel nearly as firm. I don't
know whether this is by design, or if I have some air pockets in the
lines somewhere. Loose travel is ok, but if it feels like you're pushing
on something spongy then there might be an issue. Air in any lines will
cause an issue, but bleeding the calipers should get it all out. Make
sure the car is level and the calipers are bled in the correct order. My
'87 has the ABS modulator in the trunk well, so that may change things
compared to the later cars with it under the hood.

Also I asked about the voltage drop I was getting across a
dual-diode- type battery isolator I installed. I have now learned that
there is no way to get around having the voltage reduced about .8
volts or so with this "passive component" type isolator. So since I
can't tweak up the alternator votage a bit, I will not be able to
fully top off either the car battery or the camper battery with this
device. The solution is to install an "active" type isolator which
uses series pass transistors, and they have virtually zero votage
drop. The drawback is they are about three times the price.

Thanks, Geronimo

So is it a Denso alternator? If it's Bosch, you can buy an adjustable
voltage regulator. In theory it should be possible to modify the Denso
but I haven't looked. You could also replace it with a Bosch, they're
physically a bit larger but I think the mount is the same. I'm
considering swapping the other way around on my 240 Turbo because the
space is so cramped, the 100A Bosch alternator I put in there to replace
the little 55A unit just barely fits.