New to me 940

[sam1]

Found a sticker on the back axle, under a load of crud, had 3.54 written on it.

Brake discs on the front are 287mm, they had a massive lip around the edge. Main surface was 18mm and the lip was 22mm so well knackered.

Needed new brake hoses on the rear, but one side i had to hacksaw apart as the pipe union was seized into the flexi. Dave don't suppose in all your wisdom you'd know what the thread is in the flexi pipe, i think i need one of these

https://www.halfords.com/tools/fuses...le-186810.html

My motor factors supplied the wrong brake bits - they supplied for abs when mine does not have abs so the front pads do not fit. I had already done the rears by this point and they went together fine. Just wondering am i right in saying the rear brakes are the same for abs and non abs?
And are the front discs any different with abs/non abs? The abs pads are definitely wrong!
Thanks

[Laird Scooby]

Originally Posted by sam1

Found a sticker on the back axle, under a load of crud, had 3.54 written on it.

Brake discs on the front are 287mm, they had a massive lip around the edge. Main surface was 18mm and the lip was 22mm so well knackered.

Needed new brake hoses on the rear, but one side i had to hacksaw apart as the pipe union was seized into the flexi. Dave don't suppose in all your wisdom you'd know what the thread is in the flexi pipe, i think i need one of these

https://www.halfords.com/tools/fuses...le-186810.html

My motor factors supplied the wrong brake bits - they supplied for abs when mine does not have abs so the front pads do not fit. I had already done the rears by this point and they went together fine. Just wondering am i right in saying the rear brakes are the same for abs and non abs?
And are the front discs any different with abs/non abs? The abs pads are definitely wrong!
Thanks

Sounds like your speedo is more accurate than many then!

You've got an unusual disc size, 287mm x 22mm ventilated. The problem now comes with what calipers you have and are you sure you don't have ABS? The reason i'm querying that is that my 760 has 287 x 22mm vented front discs and ABS, single piston sliding calipers. Usually the non-ABS models have different calipers, some are twin piston, others are more complicated than that! Some even have 3 bleed nipples!

Rear pads are pretty much standard whether ABS or not, usually about 3" x 2.5" roughly although ive not measured them to be 100% certain on those dimensions.

As for the thread, no idea i'm afraid. Best bet is if you have a hydraulic hose supplier somewhere near, take the new flexi hose into them and ask them to tel you the thread, then you can get the correct union to go on your metal brake pipe - i hope you have a flaring kit for it?

Any chance you can upload some pics of the underbonnet area, particularly on the drivers side behind the headlight and also pics of your front calipers?

[sam1]

When its working it might be!!

Yes i can confirm its a 287mm disc, no ABS, the front calipers are twin piston, twin brake hose and 2 bleed screws.

the rear pads i think are standard throughout the range you are right.
a weird issue that is occuring now, although i think may be due to being new dics and handbrake shoes, is the handbrake has almost 0 effort. before it was working fine when pulled to 3 clicks and the adjustment screw behind the rear ash tray was only wound out around 10mm. i have had to wind it all the way out, around 35mm to get it to only slightly bite. maybe it needs bedding in. i believe there is no other adjustment other than the main one in the center console. i was careful to reassemble the rear handbrake components as they came out but maybe ill have to take them apart again.

the brake union was a standard size m10 x 10mm i think. yes i luckily have a flaring tool from similar past experiences. and nothing is currently leaking... from the brake system at least!

new tyres on and i have gone to fully loaded pressures from the haynes manual at 2.8 bar rear 2.1 front.

speedo still no worky, got the connector out of the sensor and shorted across the contacts and the needle didnt jump (i think i read this in a diy repair section) but the engine idle did change in sound when i was tapping across the contacts... im sure ill have a fun few days figuring that out at some point.

hoping for a good 3hr journey tomorrow. i usually only do 60 mph on the motorways to save fuel and just leave a bit of extra time. so we shall see.

[Laird Scooby]

Originally Posted by sam1

When its working it might be!!

Yes i can confirm its a 287mm disc, no ABS, the front calipers are twin piston, twin brake hose and 2 bleed screws.

the rear pads i think are standard throughout the range you are right.
a weird issue that is occuring now, although i think may be due to being new dics and handbrake shoes, is the handbrake has almost 0 effort. before it was working fine when pulled to 3 clicks and the adjustment screw behind the rear ash tray was only wound out around 10mm. i have had to wind it all the way out, around 35mm to get it to only slightly bite. maybe it needs bedding in. i believe there is no other adjustment other than the main one in the center console. i was careful to reassemble the rear handbrake components as they came out but maybe ill have to take them apart again.

the brake union was a standard size m10 x 10mm i think. yes i luckily have a flaring tool from similar past experiences. and nothing is currently leaking... from the brake system at least!

new tyres on and i have gone to fully loaded pressures from the haynes manual at 2.8 bar rear 2.1 front.

speedo still no worky, got the connector out of the sensor and shorted across the contacts and the needle didnt jump (i think i read this in a diy repair section) but the engine idle did change in sound when i was tapping across the contacts... im sure ill have a fun few days figuring that out at some point.

hoping for a good 3hr journey tomorrow. i usually only do 60 mph on the motorways to save fuel and just leave a bit of extra time. so we shall see.

You missed the auto-adjusters on the handbrake shoes then? Or have you refitted them upside down? Either is likely to cause lack of handbrake or possibly the A-frame has come off the axle.

Whatever it is, you need to slacken the handbrake adjuster off in the centre console then remove the drums again and find out what's going on.

Fully loaded tyre pressures? Only if you always have 4 passengers and a lot of luggage! Otherwise the back end will bounce around like Zebedee on acid and have little or no grip plus you could damage the tyres or even have a blowout, especially in this hot weather!

Shorting across the speedo sensor connector near the back axle won't make the speedo jump - who told you that? It also won't alter the engine idle - unless you weren't checking the speedo sensor at all?

[sam1]

I managed my journey with no problems luckily.
Due to no speedo had to note mileages off the GPS for my journeys and calculated a rough 36-37 mpg over 402 miles. Based off just over 300miles @ 60mph on the motorway and 100 miles smaller roads all driving sensibly and not exceeding 3000rpm.

After driving all the way there, I started the car the next day to see a permanent lamba light. Its still on I will check the code reader today to see what it is. Probably the oxygen sensor.

I'll also take the back brakes off and have a look in there today - i was pretty confident there was no adjustment in there and from what i have read there is not.

Re speedo not working - I read this guide https://www.volvoclub.org.uk/faq/Ele...eterRepair.htm which said to short the contacts 4-5 times a second which is what i did and had no effect on the speedo. i wonder is there a way to test the speed sensor on the diff?

[Laird Scooby]

That's not bad economy but can i ask why 60mph on the motorway?

Did the engine management light not come on during driving the previous day?

Good luck with the brake shoes, don't forget to check the A-frame on the axle!

There's no way shorting the sensor contacts together 4-5 times a second (4-5Hz) will make the speedo read anything. It's a magnetic sensor with a coil of wire so as the reluctor ring passes over it, it changes the magnetic field and induces a current in the coil. Because of the inherent resistance in the coil, it develops a voltage.

I'm going to keep the figures simple so you can see where i'm going with this but at 70mph in 4th, the engine is turning at ~3500rpm, correct? As 4th is a direct ratio (1:1), that means the propshaft is also turning at 3500rpm. As your diff is 3.54:1, i'll use artistic licence to call it 3.5:1 so that means the diff output shafts (to the wheels and including the reluctor ring in the diff) are also turning at 1000rpm. On a post 91 car ('92 on basically although the changeover point exactly is a bit hazy), there are 48 teeth in that reluctor ring. That's 48 pulses per revolution or 48000 per minute. Divide by 60 (seconds) gives you 800 pulses per second or 800Hz. That's at 70mph so for a reading of ~15mph, the frequency would have to be ~160Hz - not 4-5Hz!

Even on early 7xx cars with a 12 tooth reluctor ring (non-ABS models, ABS-equipped cars had a 96 tooth reluctor ring up to 91 from ~1987) that would still need a frequency of ~40Hz to register ~15mph so even if the circuitry would recognise being shorted to earth without any voltage from the sensor, the maths are still a mile out!

If you have a multimeter that has a frequency range you can use that to test the output of the sensor. You can do it on the DC range as well but you don't get a voltage proprtional to speed. Best bet is a hand-held digital oscilloscope.

[tofufi]

Originally Posted by Laird Scooby

Fully loaded tyre pressures? Only if you always have 4 passengers and a lot of luggage! Otherwise the back end will bounce around like Zebedee on acid and have little or no grip plus you could damage the tyres or even have a blowout, especially in this hot weather!

I tend to run my 740 towards the higher end of the tyre pressures. No problems with ride quality over the last 35k miles, and this set of tyres are showing wear levels over the last 30k low enough that I reckon they'll make it 50-60k miles

Still corners ok too!

[Laird Scooby]

Originally Posted by tofufi

I tend to run my 740 towards the higher end of the tyre pressures. No problems with ride quality over the last 35k miles, and this set of tyres are showing wear levels over the last 30k low enough that I reckon they'll make it 50-60k miles

Still corners ok too!

Depends what you call the higher end Jim. All the 740s i've had in the past, i've increased the tyre pressures when i've had a big load and when running empty, they were all seriously skittish!



That was my last 740 with a serious load in it! What it looked like with the tailgate open :



Knowing i was picking that lot up, i increased the tyre pressures before i set out to the full load setting and then drove from here to Rochester to pick that lot up. Coming back the ride was more like how it is at normal tyre pressures unladen but was pretty unpleasant on the way there.

[sam1]

60 mph cruise for economy, I've always allowed for it and it saves 10-15% over going faster. I also figure the engine is more relaxed and will last longer

No the engine mangement light didnt come on during the long drive just the next morning after starting. I've just checked the codes and it showed a 1-3-1 possible crankshaft sensor on the way out maybe? It has taken a couple of goes to start it before i did the fuel pumps.

I hear you on the speedo front; I was just following what I read.

Having just taken the rear discs off again there is definitely no adjustment in there. The system on the back axle for the handbrake seems to be functioning but the holes on the small a frame thing look very worn and stretched. I am now winding the adjuster all the way out again.....

I'm not I'll get around to fault finding the speedo for a couple of weeks as i have some more mileage to do in a couple of days, 4hrs each way this time.

I've been informed of a volvo breakers off the A1 lakes autos, I may swing by and have a look around on my way to Manchester if i have time. I could do with a luggage load cover, glove box lock and possibly some other bits

[Laird Scooby]

Originally Posted by sam1

60 mph cruise for economy, I've always allowed for it and it saves 10-15% over going faster. I also figure the engine is more relaxed and will last longer

No the engine mangement light didnt come on during the long drive just the next morning after starting. I've just checked the codes and it showed a 1-3-1 possible crankshaft sensor on the way out maybe? It has taken a couple of goes to start it before i did the fuel pumps.

I hear you on the speedo front; I was just following what I read.

Having just taken the rear discs off again there is definitely no adjustment in there. The system on the back axle for the handbrake seems to be functioning but the holes on the small a frame thing look very worn and stretched. I am now winding the adjuster all the way out again.....

I'm not I'll get around to fault finding the speedo for a couple of weeks as i have some more mileage to do in a couple of days, 4hrs each way this time.

I've been informed of a volvo breakers off the A1 lakes autos, I may swing by and have a look around on my way to Manchester if i have time. I could do with a luggage load cover, glove box lock and possibly some other bits

Fair enough on the 60mph thing on the motorway, although i don't get on dual carriageways or motorways as much these days every time i do there seems to be a whole line of people doing 60mph in the inside lane that give me filthy looks as i go past them.

I've just read again what i put about the handbrake shoes and the auto-adjuster. I'm afraid i have to apologise here, hadn't even realised i'd done it until now. It's not an auto adjuster, it's the mechanism the cable pulls on to open the shoes so they grip. There is an arrow on the side of this mechanism as it only works correctly one way up, there's also a corresponding strut at the front end of the shoes that has to be fitted the right way up.
Regarding the A-frame on the axle, there should be some clearance in the holes to allow for movement but if you can reduce it then it will improve the handbrake. If not, there is a repair kit :

https://www.partsforvolvosonline.com...oducts_id=4412

I daresay if the lugs on the axle are intact you could just use the A-Frame part, if not you've got everything to repair it.

I had a read through the speedo diagnosis thing you linked to, still can't fathom how he got a reading on his speedo simply by shorting the contacts, it shouldn't be possible.

Lakes are good but i'd advise phoning before you take a detour. I was last there about 3 years ago and informed by one of the brothers that owns it they were closing the following week. As i understand it, they're still going but closure could be imminent or already happened.
If you have no success, get in touch with either Luke (360beast) or Mark (Griston64) by finding one of their "Breaking 940" threads in the For Sale section. Luke usually has something in for breaking and/or some extra bits from previously broken cars.

Most glovebox problems can be sorted by adjusting the glovebox in the dash, either up or down so the glovebox stays shut when it should or opens when it should respectively. You may not need a new latch or lock.