360 heavy braking

[germ]

i was thinking of buying discs and pads mintex of ebay they were soo cheap damn

[germ]

i think this was 1 premier-auto-components (on the bay) and the sites look dodgy

i dont think theyy have them now.


edit: http://cgi.ebay.co.uk/VOLVO-300-SERIES- ... dZViewItem

[MJ]

I've never tried locking the wheels, but on the few occasions that hard breaking has been required, it sure seemed to stop fast, and I could have braked harder.

At the time, I thought I shouldn't break harder or it would have locked, but afterwards I realised it probably had more grip than I realised. Unless you've pushed your car close to the edge, you don't really have any idea what it's limits are. I often think I'm cornering at the top safe speed, but having ridden with several others in their 300's, they sure can corner much faster.

But it does save tyre wear

[petefarrell360]

I'm in no doubt that my car could actually lock the brakes and skid. THe thing is, it's second nature for me to release the pedal just in time so that I won't skid on heavy braking and to pump the pedal to keep the wheels revolving! It's an odd thing to be able to do it, as it goes against your natural reactions, but if you can stay calm in an emergency and do it, it could save you from losing control!

MJ, knowing the limits is a good thing to learn. If this can be done in a safe and controlled environment, it can help so much in everyday driving.

Pete

[pettaw]

Yes, you should be able to lock the wheels, but if its dry and your tyres are in good condition, it's damn hard, you really have to try to lock them in order to do it.

If you generally feel there's a loss of power, then it really could be anything, but a few simple things to check.

First of all, make sure the hose to the brake servo is in good shape. They can quite often collapse internally, meaning there's less vacuum going to the servo. This will be felt as though the brakes were good the first time you used them, but if you then release and brake again the pedal will be hard. Check the hose with the car running, does it look as though its sucked in on itself?

Take off the front wheels and check the discs and pads. Particularly the inner side of the discs, as these can rust away quite happily, with the pads just polishing the rust, and not being picked up at the MOT, because they're hidden under the guards etc......If you're unsure then take one of the caliper mounting bolts off and swivel the calipers up out the way so you can see the disc clearly. Details of how to do this if you're unsure are in Haynes, but make sure to tighten to 33Nm and put Loctite on the threads.

Also if the fluid is old, then braking efficiency is decreased, so you may want to get it changed if its not been done in the last 2 years,

If the master cylinder is on its way out, you'll probably notice a slightly soft pedal that works OK, but if you put constant pressure on will sink slowly to the floor. Depending on which seal is on its way out, either gentle pressure or hard pressure will do it, but it has to be constant. Symptoms are very similar to air in the system, so if a master cylinder problem is suspected always bleed the brakes first.

Erm, not too sure how much extra I can add, but a bit of detective work is needed.

Will, the braking system was redesigned in 1986 so all that data refers to earlier models. All 300 front brakes are the same, and the master cylinder is the same, the back brakes and handbrake are different between 340 and 360. My French totally sucks, but I understood something about a dual system with two pistons in the master cylinder, so if one circuit fails they don't fail completely, but I didn't see a part about a pendulum. Any chance you could provide a brief translation for a Luddite like me

[bogbasic]

Hello, all good ideas. Some answers to queries...

The tyres are Michellins which are new and the brake fluid was bled completely a year ago (some pipes and all hoses replaced). Incidently the 1.4 was completely bled too so should be comparable.

The servo does seem to be doing something - I noticed big difference when bleeding the brakes between having engine on and off.

Shoes and pads look good. Oddly there is no wear in the front disks in spite of them being quite old (judging from thick rust on rim). Perhaps its the pads??!!

The pedal is hard (not spongy) just too hard!

Maybe I'll try new pads and if no better then look at the servo. What pads are good?

Cheers, bogbasic.

[A M R]

is this guy saying that his brakes are generally poor compared to the 340 or they have suddenly become poor?

if they suddenly became poor and were better before, change your brake fluid, and then calipers, and then master cylinder.

if they were always poor, my guess is that they will always be poor and you should just forget about it unless youre going to do some really hard driving and you need better brakes.

hope i helped

EDITED: There are other, more appropriate words to use than the chosen one!

[germ]

Translation of the part labeled FREINS! as recrested!


On the early models volvo made statement of front brake pads with out asbestos

The swidish(aka Volvo) builder dosent speak any more for the new models 340/360 the braking mechinisme, (very classique) is of front discs and rear drums but also a true duel circuit acting in diagonal and comandes at the same time the front wheels and one back.

This braking is ofcouse servo assisted and sees itself more over equiped with a distributor acting as funtion of the load on the axle. its role is to avoid the wheel locking under a strong deceleration and the differnce of the masses on the front end.

Throughout the test, the brakes have astonished me particularly by its power, its progressiveness, its directional stability but also by its hot behaviour. only small problem, at the time of braking very hardly, the car has tendency has to prick a little too much at front but without wheel locking fortunately. the action of servo does not lend either the side to criticism since it makes it possible to very easily proportion the braking for a really reduced effort.
FINISHED!
Ive proberly made like a million spelling mistakes and stuff as i have got french in the brain.

still i think iam quite good for only livin here for 3 years.
french is a very hard language and to get good you have to forget some english and learn "franglais"

Hope You Apresiate It

Cheers
will

[foggyjames]

Both of my 300s have brakes which are in great condition, but they do feel different.

Nessy (340 B14) had new rear cylinders and shoes a couple of years ago, and it feels a lot 'sharper'. The fronts are a bit weak in comparison, and it can be prone to locking a rear....although we're being fussy now. I drew it up from (sorry officer) to a standstill in under 100m a couple of weeks ago, when some peasent in a Mondeo was trying to outbrake me.

All of the components on the 360 (B200K) are older (it needs new front pads fairly shortly), but it still stops in a serious hurry (as I think Ali and Solamanda can testify!) when required, and it feels rather more balanced and secure under braking....if a little more wooly / less sharp.

Having said all of that, the 240 really does put them both to shame, despite the significant weight penalty. Very few non-sports cars had 4-pot fixed calipers in the 80s. The damn thing feels like it'll lift its rear wheels if required.

In answer to your questions....I suspect that it's something specific to your setup, rather than the model.

cheers

James

[V6 Man]

Also if the fluid is old, then braking efficiency is decreased, so you may want to get it changed if its not been done in the last 2 years,

BINGO!

Brake fluid is hygrospcopic (ie absorbs water) and does degrade with time. If you have old fluid then it will compress more and thus give less effort to the pistons and thus lower efficiency. It is recommended that brake fluid is changed every 2 years to stop this problem occuring. How many people can honestly say that they've done this? I know I can't.

[foggyjames]

IIRC, Mr Bogbasic has just put at least one new caliper on the 360, so I'd guess the fluid is new.

cheers

James

[pettaw]

Right, OK, that sounds interesting. The Discs look as though there's no wear, and the pedal is hard, but the servo does seem to be doing something.

Yeah it might be the pads, if they're a cheapy set then they may not have as good a retarding effect as good ones. Also the caliper pistons may be partially seized, although you would expect that to be picked up MOT time. Its worth seeing if you can put a screwdriver between the set of pads and just make sure the caliper pushes in and out.

Also you say they look good, do check the back side of the discs because you can get hidden rust. I had so much rust on mine, that the pad was basically polishing rust up, and yet the car passed 2 MOTS like that

Will, thanks so much for doing that. It helps a lot, I think its describing the brake reducing valve which reduces pressure to the rear brakes circuit, so the rear brakes can't lock up before the front ones do. Your translating is great BTW.

Oh: AMR, thanks mate, change everything until it works

[jtbo]

My experience, I have owned 360 for 4 years now I think and at beginning brakes were very good and sensitive, but now (ok last summer was last time I drove) they have gone worse, I need to take them apart clean all rust and then put back together and they will be fine again.
Something that should be done almost every year in these conditions we have, I have not done even once, it is lot of work and really have no space where to do it.

[bogbasic]

Hello, more ramblings. I disconnected the vacuum pipe to the servo on the 360 to see if the servo was working and this clearly showed that the servo definitely is doing a lot of good work. No servo = pedal as solid as a wall and virtually no braking effect at all - scary stuff. So the servo is doing a good job but its still quite hard work compared to the 340 which has instant braking with very little peddle pressure.

So could it be that better pads are needed just to sharpen up the brake performance??

What pads are the best for this??

[pettaw]

So presumably you checked all the other stuff we went through in this thread......