Since the headgasket job is now done it's time to turn my attention to other issues on the 940. I've been battling a soft brake pedal for ages and the brakes don't feel as strong and reassuring as they should. Compared to my folks 1990 740GL the brakes on my 940 are terrible. Numerous bleeds haven't solved the issue.
However, If the pedal is pushed hard (almost to the floor) a few times it firms up and the brakes are better for a while - up to a couple of days - then the pedal gradually goes soft again.
The front calipers (Girling) have been replaced twice with Volvo rebuilt ones - made no difference. I'm thinking there is an issue with the rear calipers (which are ATE) since the car has done 100K kilometres since I've had it and the back pads are barely worn but I've been through 2 sets of front pads in that time. Can the rear calipers be adjusted at all or are they self adjusting like the fronts?
Any advice??
Brad
91 940GL

Brad,

I have a 94 940 with the identical problem. It has had this for years also.
as well as the fact that the front end shudders while hitting the brakes at higher speeds. New cone bushings were a great help but the cause of the problem was amplified by the worn cones. I have flushed the system to no avail and nave put all volvo components on all 4 wheels. This where I am at with the problem:

1. am going to check all hoses for implosion or expansion under pressure by doing a visual as well as clamping them off one at a time

2. A rebuild of the rear calipers is on the list for sure. ( I didn't like the way they compressed just recently on new pad install job)

3. and of course the front rotors are going to be indicated for run out.

All in all, I wouldn't give up my volvo for nothin' but I have not been very impressed with their braking systems for sure. If you talk with someone who owns a 740 they will be amazed at your complaints. What's the difference? I don't know.

Please be informed that those on this board who know more than me have advised me that the 940's have a softer pedal than their predecessors. I am however sure that my problem will be the rear calipers. I am assuming that their sluggish movement is causing the wrong areas of the system to absorb the pressure which why I need the booster's help to get the pedal to go long and soft. Hope this helps. Please let me know what you discover and I will do the same for you Larry

each time I've encountered this on my 3 700s, it turned out to be master cylinder was leaking inside and allowing pressure bypass. It is an easy job, but buy a Motive power bleeder from fcpGroton, you'll never do a brake job again w/o it !!

I replaced the MC on my 940 about 3 years ago and it never made any difference - pedal was just as soft as before but at least it wasn't worse. I also use a home made pressure bleeder to bleed the brakes so I don't have to do the 'pump the pedal' business. I haven't gotten around to trying clamps on the hoses yet. Uni starts again in a couple of days so God knows when I'll get the chance.

Brad
91 940GL

Dear sherm,

Good a.m. Did you simply replace the master cylinder, or did you replace the leaking seals? If the latter, what were the part numbers for the replacement items and could you set forth in detail, the seal replacement process?

Thanks for sharing your insights.

Yours faithfully,

Spook

Looks like this is a fairly common problem. My 940's brake pedal travels about 2 inches before I can feel any braking at all. I compared that to my folks 740 which takes only an inch or less before there is noticeable braking effect.
I wouldn't get rid of my 940 either. I love her heaps - I plan to be buried in her :-)
I have heard that the 940's brake pedal is softer than others but I just think that the braking force isn't there - at least not what I would expect from a Volvo. Considering my last car was a Mitsubishi which had excellent brakes (but no ABS)the 940 definitely needs attention.
I have some hose clamps so I might try clamping off the brake hoses and see what the results are. I'll post back when I'm done.

Brad
91 940GL

I'm not so sure about a soft brake pedal being a problem with all 940's. Normally one would say this is a bleeding problem with air trapped somewhere in the brake system, but I'm not a total novice brake bleeder and I can tell you this doesn't appear to be the case. I think I've told this story before. My daily driver is a '95 940 turbo and it does indeed have a soft brake pedal, probably softer than any Volvo I've owned. Yet, my wife's '95 940, although not a turbo, has always had a nice firm brake pedal, firmer than any Volvo we've had. I've yet to figure out why this is so. First off I note that the brake boosters are a different size -the one for the 940T would appear to have a smaller diaphragm, so the brake boost power may well account for some of the difference. Turbo's of course use a vacuum pump to load the brake booster, but a vacuum gauge shows the B230FT vacuum every bit as good if not better than the B230F NA. Numerous power bleeds, a new master cylinder, a new brake booster and a front caliper re-build only achieved a marginal improvement on the 940T. I thought this might be a pad/rotor issue, but they've now got identical pads and rotors. Someone suggested there might be air trapped inside the ABS, but after numerous power bleeds and operation of the ABS system I can't imagine this being a constant factor. So, go figure.
--
Dave -940's, prev 740/240/140/120 Never overestimate what little I know.

Hello Dave:

Your post is very interesting-- I have a '92 945T with the softest pedal feel of any Volvo I have ever owned or worked on, with no apparent problems with the MC , slide pins or calipers. I'd be very curious to hear what others have done to improve this-- the brakes on this car remind me of a loaner mid-80's Chevy Caprice I got from a body shop once-- not the ideal brake feel...

Also, on an unrelated note, I went looking for the cat-back exhaust system that you wrote about for my '92 945T and was dismayed to discover that the Volvo OEM system was $442 ++ at local dealers-- with 332K km on the clock I chose to go with a Starla system from FCPgroton.com. At about $170 USD it seemed like the right thing to do with this particular car. It fit as well as the OEM system I put on my 245, but I doubt it will be around as long...

Cheers!

Brad,are you losing any brake fluid? If the pedal is getting soft it usually means air is entering the system.Find the leak and you've found your problem!If you are not losing fluid,it is probably either a failing master cylinder or possibly the rear calipers.No adjustments are required with disc brakes.


sredwine '94 940T at 194K miles,'95 945T at 160K miles

No, It's not losing any brake fluid. I should have mentioned that I replaced the master cylinder about 3 years ago and it didn't fix the problem. I guess I can try bleeding them again but I'm starting to suspect the rear calipers. Thanks for your reply.

Brad
91 940GL

I have the identical problem with my brakes - soft peddle and almost no wear on my rear brakes for the past few years. In fact, when I am going backwards down a slope and step on the brakes, I get a sound as if the brake pads are just touching the discs even though I am pressly firmly on the pedal. I will have this checked out over the next week and post again.

Dear Blue 940,

May I suggest the Master cylinder? All may appear well on the outside but pitting on the wall of the cylinder allows fluid to pass the seals and the pedal sinks. The pitting is the result of moisture accumulating in the fluid from repeated break use.

lenk