Brake Advice Please

[Kirkie]

I am situated near Oldham in Lancashire and would like to find a mechanic who can give my brakes a good looking at.
I am able to change pads etc myself, but I have a problem with pressure equalisation as the fault light is glowing.. (same as the H/brake light)
Also. Due to being between properties I do not have the facilities at home to start a wheels off investigation.
I have asked some "Classic" with a small "C" garages in the area , but they all say..Oh..its them dual circuit brakes, dont know about them mate..
So.. could someone please point me in the direction of a Volvo Guru..
There are some people I would like to pm for advice like John H, but I only have twelve posts...I am a fully paid up member of the V.O.C and wish to bring my 144 to a high standard so that I can enjoy its full potential..
My phone number is 07734 574 125 . available anytime..
Thanks for reading this. Jim.

[Triple-S]

The first thing I would do is remove then replace the electrical connection to the brake equalising block on the inner front wing (where all the hydraulic pipes go into). This has to be reset after all brake work involving disturbing the hydraulic circuit.
Haven't got my Haynes in front of me but I know it has to be done as had same problem myself years ago with my 164 .
Give that a try then report back ! Not sure about handbrake warning light though: could be low fluid or that the switch needs repositioning a bit. Be thorough though, as brakes are somewhat vital.

P

[Kirkie]

Thanks Triple S..
I have got the wire to the switch on the left inner wing disconnected at the moment as it uses the same warning light as the handbrake on !.
My problem really is that although the car is in brilliant condition, I do not have any history for it , so I am finding things as I go through it.
I have been ok with most things like dashboard lights and heater etc.
But, The dual circuit brakes are really beyond me and I want to take my grandchildren out in the vehicle.
I have a budget for the brakes and would rather invest it with a competent mechanic who has experience of the marque rather than experimenting myself. Im ok with Morris Minor brakes though.
Im not rich, or a snob, but good safe brakes are paramount for me and I do not mind replacing any item if it is required.
Im 66 now and this will probably be the car I keep till the end, at least the engine and body are good. ?

[Triple-S]

If you expected an instant reply cos you are working on the car right now, sorry - was sorting out some Volvo 140 wheels for a friend who came round.

By looking at my Haynes (thought it was in my car, which isn't here) it says to take electric supply off that pressure differential valve assembly as I said earlier, then remove the hex unit it goes on (completely) BUT it adds that the brakes have to be bled afterwards. Only then do you replace that hex unit and replace the electric lead. I run a Volvo 240 as a day-car and my light came on: brakes and fluid was fine though. My local Indy said to do as above but only slacken that hex unit until a dribble of fluid comes out then snap shut again and replace the electrics. He said it implied a bit of crud (sorry - technical term!) was upsetting the balance of the system and once bled off (not letting any air in) the hex unit would be balanced so that the light wasn't on. Sorry a bit long-winded but have a look at your Haynes (if you need one I have a spare: mail me on paultill@tesco.net if interested).

The stoplamp switch is mounted on an angle-bracket on the brake pedal (so put your head where your feet go) and can be adjusted to set to operate when the pedal is depressed. Your handbrake cables may need adjusting too (one way or the other - depends if brakes are binding when jacked up and wheel rotated). Relatively simple spanner work, but as you say with increasing years some jobs can tire one! My granddaughter is starting uni next term - it was ages ago she went in my 164 yet my youngest grandson has yet to sample that pleasure (he's 2).

Direct-mail me if snags, as I'm in and out like a fiddlers elbow.

P

[woolfie1948]

When I first had my 164 the red light did not work at all and I found the elect connection was not on the warning valve. When I connected it the red light was on but would not go out.
I read up in the green manual and it says if there is no fault in the system warning valve must be re set.
"1 Disconect the electric cable and screw out the warning switch so that the piston return to normal position
2 repair and bleed thefaulty hydraulic circuit
3 screw in the warning switch and tighten it to a torque 14-20Nm.Connect the electric cable"
I had no fault on the system so did as this and red light was out and went in when the handbrake went on. As it should.
No fluid came out when the switch was out. New switch if faulty can be gt from Brookhouse.

[140]

I would add that after removing the switch completely pump the brake pedal a few times to equalize the valve (no fluid will come out) and then replace.

[Volvorama]

Yep. Should just be a matter of unscrewing the warning sensor and then putting it back in again. 140's advice about pumping the brakes isn't a bad idea so I'd give it a try if necessary.

[dingov70]

If you have pushed back pistons to replace pads , you may simply have moved the shuttle in the valve block . Simply remove the switch where the wires fit & use a small flat scrwedriver to move the piston back . It is in the correct place when you can see a machined groove in the middle of the hole the switch fits in .

There used to be factory tools to use when performing brake services , you removed the switch & slid a fork into the valve and screwed in a retainer that the fork fitted into . The idea of the valve is to ensure if a brake pipe bursts , the valve flicks across & stops the fluid being lost on the leaking circuit & bleeding brakes or pushing back pistons can make shuttle seal of one circuit .


Hope this helps

[guitarman]

As I recently discovered when working on my 164s brakes; the bulbs for both the handbrake warning light and the brake failure circuit had been removed....
My car is an auto so I never use the handbrake so I never realised the bulb was missing. I replaced both bulbs and the handbrake bulb would not go out...I checked the handbrake circuit plunger switch, working fine; then in my 164 service manual found that handbrake and brake failure lights share the same circuit.
So I checked the switch that lies, as has been aforementioned in the block between the two brake circuits. It looked fine, my brakes looked fine....I wondered why the plunger was nylon and not steel.....then I looked closer at the nylon plunger, the end was burred over.
Using my powers of deduction* I realised that the switch was designed to be tamper proof. The little buffers at the end of each brake circuit, inside the block have grooves in them; so if the circuits become imbalanced a buffer will shoot across and the groove will engage the nylon buffer cutting about 1/8" off the end and activating the brake faliure light...and handbrake warning light.
Only when the circuits are equalised and a new switch with the correct length plunger has been introduced will the circuit be cut and the lights go out.
Scandix and Amazon cars both do the plunger switch at a hefty price, being impecunious I purchased mine off eBay . com and it was still half the price with the block too. The seller kindly measured the length of the nylon plunger and it had never activated. Considering it had been in a p1800 for years it says much for Volvos brake systems!

[guitarman]

To go back to your warning light then; you will really need a new brake failure switch, unless you want to live dangerously and just remove the connector. You'll need to bleed the brakes correctly, if you have a service manual it will show you how, there are about 8? bleed nipped and they need to be bled in the correct order (there is a site on the Web that shows how). If you haven't already I'd suggest new dot4 brake fluid.