Replacing 240 Front Brake Pads

familyman

I thought the (original) front brake pads on my '91 240 had worn through at 50,000km. But the scraping has stopped again. So maybe it was just a rock that bounced out. Anyway, it's been a few years since I've done brakes. So I watched a couple of youtube clips for a refresher, and had to come and ask:

1. A guy in one youtube clip, puts grease on the contact points of pad/caliper locking pins. Is that correct? I would have thought heat from braking would soon melt the grease and have it possibly drip onto the rotor/pad?

(I use the red anti-squeal goop on pads if I know they have a habit of squealing. But nothing on the pins. Pretty sure the mechanic I use sometimes doesn't put anything on the pins either.)

2. In the past I've just pushed the brake pistons back by levering a screwdriver or two between the old pads, before pulling them out. But until recently I've been a cheapskate too. Do you guys see any benefit to using a piston compressor tool?

3. I'll have to dig the Haines out, but is anyone aware of a step-by-step procedure online? I usually start, and if I find I need something go and order it online and wait. Problem is, with one car now and living rural, I can't do it that way. (No second car to drive.)

4. Have always owned 1970s 240s with solid rotors. Can you skim (lathe) vented rotors, or do you just buy new ones? And where from/brand? (They're original with original pads so would not have been skimmed before.)

5. Is there any point in using an on-car lathe on 240s?

6. I saw a UK clip of a guy using an on-car lathe. He said he skims even brand new rotors. Is that necessary? (Can't help but wonder how we all drove cars with vibrating brakes before on-car lathes came along.)

7. I usually reuse the same pins, retaining clips, and springs until they're ready to fall out in a strong wind, lol. Do you guys reuse, or replace? If replace, where's the best place to buy them (after postage)?

8. Mechanic once said to replace bearings when doing the brakes. Yes, no? Or just check for play/scoring and repack with grease?

9. I said I used to be cheap, right? ;-) Don't think I've used Locktite on caliper mounting bolts. Should I?

10. Months ago I kept a master cylinder cap to make a pressure bleeder. I've been (very) casually watching for the fitting needed, to seal the pressure bleeder hose to the cap. Has anyone come across something that would work? I'm thinking it would need to be two pieces - one that screws inside the other, with a rubber washer or two between?

11. What effect does solid/braided brake lines have on the drive comfort of a daily driver?

12. Where to buy caliper rebuild kits and/or new calipers if that becomes necessary? (I'm assuming it's not worth getting calipers overseas after postage?)

tbro

1/ Nope
2/ Big flat blade screwdriver
3/ Wheel off, push inner pad in all the way, then push outer in ,both pads will equalise, unbolt caliper mount bolts and remove whole caliper, remove rotor and clean mount surface on hub (VERY IMPORTANT) fit new rotor after brakecleen off the anti rust stuff. Bolt caliper back on, using Blue locktite, refit OLD pads and push inner all the way in again, remove old pad and fit new pad, do the same with outer. refit slide pins and clips. Do 1 side at a time, I always suck some brake fluid out of the MC with a big syringe. do the same on other side. Then your ready to change the fluid. I use the gravity system, I hate pumping master cylinders as your going to push where the cylinder hasn't been before and that can cause failure. Gravity system, suck the MC dry and refill with new Dot 4 fluid, open 1 bleeder at a time until clean fluid comes out, this can take a while but that's why GOD made coffee, have a cup or three, just don't let the fluid run out in the MC.
4/ see 3
5/ No
6/ no
7/ reuse
8/up to you
9/ Yes
10/ go to Pirtec/Enzed and tell em what you want to do
11/ Road car None, track or race car yes. Most car suffer from firewall flex so fit a MC brake and retry. All the cool kids run braided so up to you. Me, I get new rubber one made up @ the brake place.
12/ Same brake place that you buy your other stuff, maybe Angus or Ash.

perko

I mostly agree, but a few extra points:

1. Movement in these points is minimal, no need for it. Better to get everything nice and clean beforehand

3. Just go by the haines procedure. Be aware of the fact that parts which aren't usually replaced when doing a pad change may fail from being moved further than they have previously.
I recently was changing the pads/rotors on a bike and had the caliper seals fail when I pushed the piston back in to refit, was not something I expected or had parts for.

8. I would just check them. You may be able to find a replacement interval for them and if it's similar to the interval for the rotors, and if they are pretty cheap you may as well I guess.

9. Probably a good idea, I do if I have some or remember to buy it, if I don't then I don't bother, yet to have any calipers come loose (not that the absence of failure is good rationale for doing the wrong thing)

11. None. New braided lines will be just as good for feel as new rubber lines. The reason for having them on race cars is the fact that they're much less likely to be cut by debris. They should also last a bit longer than rubber lines before becoming soft and expanding under pressure. The main reason that everyone who fits braided lines raves about them is that they usually replace ageing rubber lines so you're replacing old for new.
That said, if I am buying new lines and can get braided for close to the price of rubber I'll go for it.

12. Brake shop/ebay.

Philia_Bear

Point 11

Flushing brake fluid with new high quality dot4 fluid will do more than replacing lines will

For a 240 flush a minimum of 2L of fluid to get out all the old stuff

I reccomend a blue fluid so you can see easily when all the old and crap fluid is out

You may even want to remove the master from the car so you can properly wash it out as there is likely to be lots of gunk in it

gavinh

Philia_Bear;82248 wrotePoint 11
Hi
Flushing brake fluid with new high quality dot4 fluid will do more than replacing lines will

For a 240 flush a minimum of 2L of fluid to get out all the old stuff

I reccomend a blue fluid so you can see easily when all the old and crap fluid is out

You may even want to remove the master from the car so you can properly wash it out as there is likely to be lots of gunk in it

Good point @Philia_Bear I generally go through at least 1 bottle of fluid when doing the line never thought of the blue brake fluid or cleaning out the master cylinder

familyman

@tbro - thanks. :-)

a. When you say to clean everything beforehand, do you mean clean with Brakecleen before you start pulling them down? If so, why not clean after disassembly?

b. When you mentioned both sides equalising... Do you mean push the inner in all the way, then the outer in but only far enough until the are about the same? The reason I ask, I'm not even sure if it was a Volvo... But I did a car once where I pushed one side in, then the other, and the first side came back out again. So I kept alternating until both stayed in. But then found the gap was much wider than needed to slip the pads in. So I didn't do that again. Is that what you mean?

c. When you bleed by pumping the pedal, there's an order to open the bleeders. You said you use the gravity method. Does that also require opening the bleeders in a certain order, or you do open only one (which one?).

d. Couldn't see #4. Can vented rotors be lathed? (I figured yes, since you answered an on-car lathe isn't necessary, but wanted to check.)

e. Also, anyone know what they coat rotors with to prevent them rusting (l-o-n-g term)? You see, the local mechanic charges $14 just to remove a tyre from a rim. So I bet a rotor skim costs nearly the same as buying new. So I'm thinking about buying and fitting a new pair, then skimming the old pair later when I see another mechanic much further away but cheaper. (So I'd have to prevent the spare set from rusting between swaps - a few or several years probably.)

@perko

Yes, thanks for the reminder, lol. I did that with a car a couple of decades ago... Pushed the brake cyclinder in, and the rubber covers popped off. Maybe that's what 'b' (above) avoids?

f. So why is on-car lathing unnecessary for 240s, but other cars need it? Something different about the way the rotors are mounted?

g. Re: Pirtec/Enzed... Someone mentioned making a pressure bleeder. Who was that... [searching]. Say, @nickm - have you made a brake fluid pressure bleeder? You mentioned Bunnings... Do you happen to know what fitting you used, to seal the hose to the master cylinder reservior cap? Or did you just fit a tyre valve, and shove the pump's hose over the tyre valve thread? If so, do you need to stop it popping off with a hose clamp, etc.?

@Philia_Bear - thanks. Yes, I've seen a mechanic use a different colour fluid each time so he can easily see when the new comes through. The brakes work fine. Best brakes I've had on a 240. (Except when you use the parking brake to drive around because you think the front pads are worn through, go into a slide in the wet because a tourist ahead slams his brakes on before entering an empty roundabout, and you nearly end up in a paddock.) I just thought, car is a '91, original lines... Probably won't swap them yet, but it's good info to bookmark for later. ;-)

h. The master cylinder (and fluid obviously) was replaced 1-2 years ago. Would there be muck in the MC so soon? What do you use to flush it? (I'm thinking not degreaser because it would leave a residue.) And then how to dry it without starting corrosion?

egads (she/her)

For G, this is the guide I followed and the bleeder is still running strong 4 years later

http://faculty.ccp.edu/faculty/dreed/campingart/jettatech/bleeder/

Don't be too crazy on size of fittings as US sizes aren't as easy to find in bunnings but you can get very close.

jamesinc

You can have vented rotors resurfaced, I did it once on the 740 via Repco. I don't think it's really very worthwhile though, unless you've somehow warped a near-new rotor, or you have ultra expensive rotors. Just buy new rotors.

familyman

@James Ok, thank you. Sounds like rotors are a lot easier to find than I've been led to believe by mechanics/supercheap/etc. Are there any brands I should avoid?

Vee_Que

The reason you do bearings is because you change the rotors which are the hub iirc.

familyman

Ah, ok. So if skimming, you'd remove the bearings to avoid metal shavings. And if new you have to fit them. So in both cases may as well put new ones in I guess. Ok, thanks. :-)

jamesinc

@familyman I have Brembo I think on mine, no complaints. I used to run RDA but found they wore out quickly. @AshDVS can source a number of different brands for very reasonable prices.

familyman

RDA - check. I think I've heard that before somewhere actually. Thank you.

I really need to get out to the garage and check the pad thickness. The grinding has stopped. But I've had that happen before temporarily too. Does 50,000km on original Volvo pads sound early/late?

Philia_Bear

Some recent experiences have had the rda slotted at half the price of the dba slotted rotors so take price into serious consideration as well as brand

familyman

@jamesinc - Spoke to supercheap. They're recommending DBA front rotors. They have two types listed in that brand, and they have no idea which one I'm supposed to get. LOL! One is $30, the other $83.

familyman

LOL. Just spoke to DBA. They don't make either type of rotor anymore. So start again. Supercheap has:

ADB
Bosch
IBS
Protech

Any I should avoid/prefer?

jamesinc

I mean Bosch don't make anything bad do they?

In terms of working out which rotor, the key words are "Vented" and "Girling caliper". The two types on offer are normally vented or solid, but only the oldest Volvos have solid rotors, I think after about 78-79 everything went vented.

familyman

Yeah I said that to SCA. I found out what the difference was myself, later. The dearer one had an extra "S" for "sport" = grooved face.

Anthony

Step 2 is use multi grips to squeeze pads against calliper.

Making up a pressure bleeder is most worthwhile.
I should write a tech article on it.

familyman

Anthony;85363 wroteStep 2 is use multi grips to squeeze pads against calliper.

Thanks.

Making up a pressure bleeder is most worthwhile.
I should write a tech article on it.

Definitely.

I've been sick. So I may wind up getting the mechanic to do the brakes. But in regards to using a pressure bleeder... I've been wondering if opening the bleeder valves in a certain order is still required (on a 240). I don't understand enough about the fluid flow through the system to answer it myself. But if that is not required and building one makes it a one-man job as well... what a valuable tool to have.