240 soft brakes - please help!

[Nicholas Lewin]

Hello all - really appreciate your advice/thoughts on this one...

The brakes on my 1991 240 estate were firm, positive and worked as they should do but needed maintenance

4 x new calipers, pads all round, rear discs, 6 x new flexible hoses were fitted along with with fresh brake fluid. When I collected the car, the brakes were shocking with several inches of brake pedal travel

I returned the car and this time additionally a new master cylinder was fitted. The brakes are better with less pedal travel. However, the pedal still moves 2-3 inches before anything happens, and probably nearer 6 inches if any real braking is needed - it's borderline terrifying!

With the engine off, the pedal can be moved and with the engine running moves much further. The brakes are smooth, don't pull and are better after about 500 miles of mixed driving (the discs/pads have bed-in)

The brakes have been bled at least four times now. So what's going on? Any help/thoughts/advice please?

Nick

[eternal optimist]

If you out your foot on the break and press down then start the engine, it’s normal for the pedal to sink further until it firms up again - that’s a sign the servo is working.

If you release the pedal then press it again, it shouldn’t go down as far as before you lifted it.

Assuming the pedal stays hard when you press it down, I’m not sure you have a problem with air that needs bleeding. If it is at all spongy, then there’s still trapped air. That can happen when the calipers are fitted on the wrong side of the car such that fluid enters at the top and the bleed nipple’s at the bottom, below the fluid inlet. Bleed it as much as you like, it will stay spongy.

[morsing]

Hi,

I had this problem for years with my 240 and it turned out to be the anti-squeal shims. Take them out, you don't need them...

Thanks

[classicswede]

Because the system has been drained (best not to unless unavoidable) the spider block will need bleeding

[Nicholas Lewin]

Thanks to all of you for input - very useful

A couple of local journeys later and the brakes are certainly biting better - in other words they are bedding-in just fine. The problem is to get that bite (and we're not talking unduly heavy braking or a load greater than two adults) I need to use 3 or 4 inches of travel on the pedal and at one point when I needed a bit more brake quite a bit more. That's not right to me...

So, Dai, what's a spider block? Please!

Cheers all

Nick

[loki_the_glt]

On the near-side chassis leg, if you follow the pipes from the master cylinder, you'll find a piece of kit with 8 pipes coming out of it. This is the "spider block" or "octopus" and it splits the fluid among the various calipers.

There is also a switch on the unit, made of nylon so very fragile. This switch needs to be cracked open to let the valve centre itself; you may(probably will) need to re-bleed the brakes themselves afterwards if any air gets into the system.

[ladytmoney]

Hi there! I am new here. Bought my first car ever a few days ago, at age 47! (Been living in NYC for 30 years). Got a used 1991 Volvo 240 and had it at the mechanic's to bring it up to speed to be road ready. I just need safe and cheap wheels, I had no idea what a great car and legacy I have stepped into. About 15 minutes after taking it fully fixed (new shocks, new coils, new exhaust system, fixed idle air control valve and a ton of wiring issues), I went to step on the brakes and the pedal went straight to the floor! I kept pumping and pumping it in disbelief as I grew closer and closer to the car in front of me, and finally the brakes starting gaining some resistance, and then worked. Needless to say, I went straight back to mechanic's. He double checked everything and it all looked good and said maybe it was air in the brake line and not to worry. Then, 5 days later, took it on a longer drive (4-5 hours of driving in total, but broken up), and then the brakes failed me in rush hour NYC highway traffic aka VERY dangerous. It's a miracle no one was killed. The brakes did NOT come right back, but did about 20+ minutes of sitting on the FDR highway with hazards on. I was told by the mechanic that I should replace the brake master cylinder with the resevoir that has the sensor for the brake fluid. Can you please advise? Thank you.

Originally Posted by morsing

Hi,

I had this problem for years with my 240 and it turned out to be the anti-squeal shims. Take them out, you don't need them...

Thanks

[Bob Meadows]

Firstly I would get a new mechanic: ~ air entering the system needs to be sorted ASAP- as you have found out!

Check the obvious first- any fluid leaks at the unions.
Master cylinder seals may be on the way out
Slave cylinder seal as above.
Servo fitted? Check the one way valve & associated pipe work.
Are the fluid levels correct (if old then change it)
Check the brake calipers on each wheel to include the pads & disks and the function of the same.

A manual is a useful guide to all the above but be systematic, the brakes are quite straight forward the obvious inspection may lead you to the solution quickly.
Good Luck.

[Stephen Edwin]

It sounds as if your car has been looked after and/or worked on by people who have not followed EXACTLY the best procedures specified by Volvo. I have followed all of this thread, and other discussions, re brakes for Volvo 240 cars. And for Volvo 240 brakes hydraulics it seems to be ESSENTIAL to follow EXACTLY the procedures specified by Volvo.

This thread illustrates how far things can go wrong if good mechanics do whatever they would do on other cars. Especially if they then make more mistakes trying to solve the problem.

Bob has given you excellent advice. And. There seem to be three little things in particular.
1. There is a sequence for bleeding the brakes. It really matters not just the sequence of wheels, but the sequence of the individual bleed nipples..
2. Jacking up the rear of the car for bleeding the brakes. So that air bubble(s) do not form or lodge in a particular place in the brake system.
3. Specific installation procedure for the master cylinder. See Nick'e explanation in this thread.

If the brakes have been messed up you could find a Volvo 240 specialist and spend possibly a lot of money. Sorry but that is my honest assessment of what is probably the situation.

There are people in this forum who can give you seriously good specific advice. They might say that a problem like this is VERY difficult to diagnose without having the car available to work on themselves.

Bottom line. As you have said, you need SAFE and cheap wheels. Whatever happens, all the best to you. And welcome to the forum




.

[Othen]

Originally Posted by ladytmoney

Hi there! I am new here. Bought my first car ever a few days ago, at age 47! (Been living in NYC for 30 years). Got a used 1991 Volvo 240 and had it at the mechanic's to bring it up to speed to be road ready. I just need safe and cheap wheels, I had no idea what a great car and legacy I have stepped into. About 15 minutes after taking it fully fixed (new shocks, new coils, new exhaust system, fixed idle air control valve and a ton of wiring issues), I went to step on the brakes and the pedal went straight to the floor! I kept pumping and pumping it in disbelief as I grew closer and closer to the car in front of me, and finally the brakes starting gaining some resistance, and then worked. Needless to say, I went straight back to mechanic's. He double checked everything and it all looked good and said maybe it was air in the brake line and not to worry. Then, 5 days later, took it on a longer drive (4-5 hours of driving in total, but broken up), and then the brakes failed me in rush hour NYC highway traffic aka VERY dangerous. It's a miracle no one was killed. The brakes did NOT come right back, but did about 20+ minutes of sitting on the FDR highway with hazards on. I was told by the mechanic that I should replace the brake master cylinder with the resevoir that has the sensor for the brake fluid. Can you please advise? Thank you.

Good morn and welcome to the forum,

I'm sorry to hear your new wheels have turned out to be neither cheap nor safe.

There is nothing specific to Volvo regarding the brakes on your motor car, all cars with hydraulic systems do much the same so any workshop should be able to sort it, or even better do it yourself (it is a good idea to gain some understanding of the motor car).

Like Bob said above, be methodical. Do the simplest and cheapest things first before you start changing expensive parts, so bleed the brakes (it could be some trapped air). This is cheap - get yourself a vacuum pump (cost about $15) and a quart of DOT4 (cost about $15), it will take about an hour on your motor car and may well show up any leaks. After that just check through all the stuff Bob mentioned - Volvo 240s are really simple cars, that is a good thing when trying to fix them.

Good fortune,

Alan