Master cylinder
 

Hello everybody,

So I figured out my last problem(start and stop thread) and as the car sat for two week I noticed the master cylinder is leaking. Right where the plastic container meets the metal valve. Can you just change the washers there or just get a new unit? If so, is after market ok?

Thanks,
Mike

1991 740 T sedan, 177k.

So anyone replaced the seals from the fluid container part to the valve? If so how hard is it to remove the fluid container to change these out?https://www.ebay.com/itm/Brake-Maste...%7CModel%3A740

https://www.iforexgoods.xyz/master-c...tm?language=en

I believe that fluid cylinder is just press fit.

looking at the parts catalog I'm seeing several different master cylinders and containers, that use different seals. with ABS, if your fluid container is sort of 'boat' shaped (tapered on the end facing the front of the car), then its probably sleeve 1221713 (you need 2) and reservoir 6819672

there are part changes in 1992+

Thanks pierce,

It does not have abs, at least as far as I know, does not make any mention of it anywhere on the car (brake pad, manual) and have never felt the abs kick in, which I def. would have around where I am.

Do you think I can just change the sleeves w/o changing the reservoir? The reservoir is boat shaped, tapers toward the front of the car. It has the 4 line hook up on the valve.

Thanks,
Mike

every 740/940 i've ever seen had ABS but I'm in the USA, where our cars tended to come with more options.

if you have ABS, there will be a ABS pump/relay/solenoid assembly forward of the left strut tower under the hood, its pretty obvious and generlaly says ABS on the black plastic shield, has a bunch of gold colored brake lines going to it.

My 89 740 GL purchased new did not come with ABS or air bag. Purchased in NY.

I def. do not have it then, and this Volvo has a sticker in the rear c pillar window on passenger side...something about Volvo exchange vehicle or special import? It says "SPECIAL DELIVERY"..I can see it on my thumbnail pic, when I enlarge it. It is a factory sticker, circular.. I can take a pic of it and post. It looks like it has been there since new. It really held up good considering the age of the car.

I reside in north Idaho and the car is from this area.

I am ordering the sleeve seals, for 10 bucks worth a shot.

https://cimg6.ibsrv.net/gimg/volvofo...9d84226218.jpg

You can see it in rear passenger window, if you zoom in on it it is legible.

That's a European delivery sticker. US spec cars delivered in Europe at the factory, aka Special Delivery, Diplomatic Sales, etc.
740 started to have airbags in late 1988 with the Turbos, and ABS about the same time frame, the NA cars got them a year or so later, if memory serves, my new '89 740 turbo had a bag and ABS...
Your 740 has 960 wheels, half inch wider than the regular 740 wheel for 1991. Volvo got cheap and dropped the 16" Hydras from the 1990 Turbo for the 1991 model year...

those 960 rims are very good quality, they seem much tougher than the 'aries rims most late 740/early 940's had.


the Hydra rims lev mentions:
https://photos.smugmug.com/By-Date/2...MG_8237-X3.jpg
(not original on that car)

the Aries riims that came on this 1992...
https://photos.smugmug.com/By-Date/2...1030543-XL.jpg
(2 were badly bent, hence I swapped for the Hydra)

Thanks guys. Hmm...have to wonder when the rims were swapped. I use those rims in the summer and I bought a set for winter, they look like the Hydra rim but with straight spokes. Have to take a pic to show you.

wild guess, the car came with steel rims and they had an opportunity to get the 960 wheels cheaply.

No Turbo ever came with steel rims in the US market. 1991 740T probably had Aries, all the 1990 740 Turbos had Hydras but for '91 Volvo went cheap. These 960 wheels, cant't think of their Volvo name, are 1/2 inch wider; the PO probably hated the Aries as much as I do, I get rid of them on all my cars for Hydras or Adharas...

https://cimg8.ibsrv.net/gimg/volvofo...193e14185a.jpg
This is what I am running for winter rims:

Actually, these Dracos were the standard 1991 740 T rims, not Aries... Now that I see them I remember...

yeah, aries was standard in 92, or at least thats what my 92 had on it

Update: I changed out the two seals on the reservoir to the valve cylinder, took about 5 minutes and no more leak! The reservoir does just pull off. Make sure you have a container to catch the brake fluid. I refilled with dot4 fluid and went for a test drive, good to go. Good pedal pressure and no more leak. No bleeding either.

thanks for the update and great result!

Update to the update...started to leak again, when the weather changed, got real cold in October here. So I changed them again and it is all set again. This time when I went to order them they were only being sold as singles, so it was about 20 bucks this time.