360 heavy braking

[bogbasic]

Hello, I have an '88 360 and an '88 340 (1.4) and the brakes on the 340 are really sharp but the 360 brakes requires heavy pedal work and it won't skid when I do an emergency test stop (with nothing behind, of course). It passed the MOT in this condition.

I then took it to a volvo specialist and they tested the brakes again and found nothing wrong. I assumed this difference might be because the 360 was a lot heavier than the 340 so it would need more pedal power to stop it but a look in Haynes manual today shows that the 360 is only about 90 kg heavier, I think.

Any clues much appreciated (servo? master cylinder?) and has anyone noticed this sort of difference between 340's and 360's?? Should I live with it, as the garage told me?

[SoLaMaNdA]

What tyres on each car? My 360 will only skid if I literally stamp on the pedal at speed (dry road).

[petefarrell360]

I have both a 360 GLT and a 340 1.4 GL Vario, and I can say that they do feel very different. The 360 in general does feel more planted and heavier, especially under braking. The 340, which doesn't have a rear spoiler and does have a smaller and different fuel tank design, feels less planted on cornering and the rear feels lighter. It does feel different on braking, but then it's a vario, so I can't select a gear to aid engine braking, although the vario system will act in a way to do so, just not as I choose to control it.

However, ignoring the vario transmission, it does feel better on braking. My 360's brakes will pull the car up and stop it very well, and I consider not locking the brakes and not skidding a good sign that you've got more grip. I have wider tryes on my 360, 195's, of what I consider to be a good make, one that I trust and know now. So there's more trye in contact with the road.

My 340 is on Pirellis, which personally, I'm not a fan of, it just happened to be that they have plently of tread left, in fact they are nearly new. I've had bad experiences with P6000's and if it had those fitted, I'd remove them!

The 360 does feel as though it requires a bit more braking pressure on the pedal, almost a spongy feeling, but they work pretty well and do stop the car as required.

If it's been tested by a Volvo Specialist and passed an MOT, and does pull the car up evenly and within safe distances, then in theory all is good. However, no one knows a car like the person who drives it most and owns it. If it doesn't feel right to you, or you're not confident with it, then it's worth investigating.

What's the condition of the brake fluid like, when was it last changed? It's something I need to do on my 360. Brake fluid, as I understand it in a DOT 3 or 4 form will absorb moisture if it gets into the system, but of course it can't take it forever and overtime it will deteriorate, and it's a fluid change that is often overlooked on cars.

I'm no expert on brakes, but my limited knowledge of the workings is that it's not going to be easy to spot a master cylinder problem from looking externally in many cases. You may not be losing brake fluid, or needing to top it up, as it's only moving from one area to another due to a bad seal. If your pedal goes right down to the floor or needs pumping to keep it operating as it's losing braking pressure, then it's a bad sign.

The servo shouldn't affect the braking effect or how good it is, it'll just be that you'll need to apply more pressure....... which is something you did say about, heavy pedal work. So, if you pump the brake pedal with the car switched off, then with your foot still on the pedal start the car, you should feel a difference in the pedal.

How good are the pads and discs?

There are many factors that can affect the braking, so by starting with those it should help get to the problem if there is one.

I expect someone with more knowledge than myself will be along at a more sensible time of day to add more info and help!

Pete

[SoLaMaNdA]

I would agree, if you're worried about the brakes bleed them - they probably won't have been done for years.

[trabitom99]

Not being an expert on brakes either I hate to speculate - however having recently had the unpleasant experience of a brake master servo pack up on me in a '75 Merc 280 your problem sounds different to the one I had. The pedal felt really spongy (not hard) and crept nearer and nearer to the floor until there was barely any braking effect left at all - really horrible, luckily it happened in a stop-and-go traffic jam.

As to my 360, I experienced a noticeable loss in braking power after the local mechanic fitted non-Volvo front discs. The rear wheels still lock fairly easily under harsh braking, now that you mention it, I haven't had the front ones lock up for a long time ...

The last time I drove a 340 is a while back - so I'm afraid I can't really comment on the differences between the two.

[dalahare]

Probably just different pads mate, Pad compound makes a massive difference to brake perfomance.

[SteveP]

I'd probably try replacing all the consumables... my current 360's brakes are pathetic in comparison to my old car, which could lock up even at 70mph on a dry road - and that had new pads, fluid and rear cylinders.. afaik.

[germ]

Locking up the wheels isnt a good thing as it looses traction thats why abs stops this

apparently the 360 has a different braking system there is a mechanical pendulum system which stops the brake locking under heavey braking
( basically a old version of abs - not electronic)


the way i know this is becouse i read the french technical data on the site


http://www.volvo300mania.com/test1.htm

its in french but it explains that theres a thing that stops the wheels from skiding

friens = brakes

Dont know if this explains it but i think it could be this apparently not many car manufactuers usesd this.

Cheers
will

[SteveP]

Obviously locking up the wheels isn't a good thing, but if my previous 360 was able to do it - then so should this one - and it can't, so I assume there is some sort of inefficiency in the braking system...

[MJ]

What years were both your cars Steve? I know they're both Mk3's, but we all know 300's have all sorts of differences, even when they're similar ages (thinks of the fuel filter thinge mentioned recently)

And germ, I believe ABS is designed primarily to allow you to steer even under very heavy breaking, whereas with locked wheels you keep going straight. I guess it may help breaking distance a bit as well, but theoretically you can stop faster without ABS, if you break just the right amount so the car doesn't quite skid, but is just on the edge.

[germ]

What years were both your cars Steve? I know they're both Mk3's, but we all know 300's have all sorts of differences, even when they're similar ages (thinks of the fuel filter thinge mentioned recently)

And germ, I believe ABS is designed primarily to allow you to steer even under very heavy breaking, whereas with locked wheels you keep going straight. I guess it may help breaking distance a bit as well, but theoretically you can stop faster without ABS, if you break just the right amount so the car doesn't quite skid, but is just on the edge.

very true but i was trying to explain the system that the 360 has and compairing it to ABS as the 360's system is rare, steve you may have somthing wrong with your brakes who knows i am just saying what it says on the french side of the forum in technical IT COULD BE THAT thats all

I am not very good at explaining sorry

[SteveP]

Theres definitely something wrong with my current brakes - they need replacing! But what I'm saying is a 360 system SHOULD feel strong, and my old black car was closer to what it should be than the saloon. I think replacing the braking consumables would be a good start - and give a massive difference in performance!

[Ronnie]

A 360 should stop very quickly if you stamp hard on the brakes - and yes you should be able to lock up all 4 wheels if you want to. The servo assist is very good on the 300 while maintaining lots of feel.

If you're finding you need to use a lot of pressure on the brake pedal I'd look at the servo side, If that's not the problem, then as others have said - I'd look at pads/shoes/discs. There's a lot of this stuff on eBay at the moment, including very cheap Mintex pads.

[SteveP]

Be warned with the Mintex pad sellers on ebay, my 'Mintex' pads came as standard replacements - I was not impressed... although I did get Mintex discs from the same seller for cheap!

I can dig out the seller name to avoid if people are thinking of bidding on some!

[Ronnie]

Cheers for the tip, Steve!