My rear brakes are shot. I let them go too long so they are grinding & cutting up the rear rotors something lovely... So I bought new pads & rotors.
My question is, should the rear rotors be vented? The ones I just received are thin solid metal. I never did brakes on an 850, but all other rotors I have seen are vented. Did I get the wrong ones or something? Or are they ok?
Thanks

 

The rears are solid rotors.

 

Hi Endee,

In general, rear rotors are of solid types. 850s are also solids, as M. Tech has noted. Only certain luxury cars and ultra-performance sport cars have vented rear rotors. Economy cars still have drum-type rear brakes. On the other hand, almost all parking brakes are still of drum types, there are brake shoes inside the discs.

Before proceeding, make sure to replace the hardware (retainer springs, pins, shims and caliper bolts). Some people noted that half-shims are the way to go, but I originally had full-size shims and no squeak was present (but the new shims are of half-size). I used cv-joint grease to stop squeak and it worked better than any "disc brake quiet" compound. The reason is that cv-joint grease is molybdenum-based, which is used for extreme pressure, but silicone-based grease seems to work just as well.

Good luck,


JPN

 

Yeah, the e-brake being an integrated drum, I am used to. I have that on my 300zx TT. But they were vented, even stock. I now have a 13" big brake kit on the front & drilled on the rear with that car tho. The 850 is a different story...

Thanks for the tips too. I will pick up some CV grease.

 

Hi Endee,

When you buya cv-grease, make sure that it is of molybdenum-based (most are of moly-base anyway).

You will also need either a C-clamp orlarge Vise-grip to push back the piston so that the new pads can be installed without resorting to violence. You will also need a pin/drift punch and a hammer to remove the retainer pins. Additionally, the caliper bolts require torque wrench to be accurate & safe.

When putting the grease, use it everywhere EXCEPT the friction surfaces. I used it on the rear brakes and the squeak stopped forever. Also, you may want to wipe off the new rotors with alcohol or brake cleaner, as some new rotors are applied with anti-corrosion material.

Brake jobs on 850 are straightforward, so you'll be fine. Just make sure to test the brakes before hitting 65 mph. Also, avoid hard braking for the first few hundred miles. If the brake fluid is more than 3 years old, I would replace it as well.

Good luck & safety first,


JPN

 

Is it necessary to change the brake fluid every 3 years? I didnĀ“t know that.

 

Hi Yod...Axel,

Yes, the brake fluid needs to be replaced at certain interval. 3 years is actually a bit stretched. Owner's guide says to change it once every 1-2 years or 150,000 to 30,000 miles. Some countries have regulations that mandates that the fluid be changed at certain intervals. (In Japan, I think it is every 2 years). The main reason for this is because brake fluid is hygroscopic, means it absorbs moisture and lowers the boiling point. If left too long, it also forms gunk or causes internal corrosion.

Brake fluid is neglected too often in the States, don't know why. Many cars have original fluid, even after 10 years or longer. I assume the reason is because 90% of drivers (the number is based on my prejudice) never bother reading the owner's guide, thinking he/she knows enough about cars while the fact is that most of them don't know a thing. Then, who are the rest of the 10%? Well, I assume they are either professional technicians or enthusiasts. You can witness this fact by watching how people react when the engine doesn't start; they'll try stepping on the gas pedal repeatedly while cranking. The correct procedure is tofloor the pedal, hold it there while cranking, and after the engine catches, gradually release the pedal. To this day, other than myselfthere was only one person who knew the correct procedure, and it was a young man in college. Also, as you know, 90% of drivers try to connect the negative jumper cable directly from battery to battery, instead of looking for a good ground in the engine compartment.

Anyway, Iusually change the brake fluid once every 2-3 years. Also, after the fluid bottle has been opened, it must be used immediately and any left over should be discarded as it may have absorbed moisture.


JPN

 

Wow, I connect jumper cables to the negative post I've only changed my transmission fluid onceand I have never changed my brake fluid. I'm feeling pretty stupid right now, but at least I am part of the 90% of people. I don't pump my gas pedal when the car won't start though. I just say damnit and take another car.

I swear if it wasn't 10 degrees outside right now I would go change my brake fluid. Anybody have directions on how to do it? I'm serious I will do it, and I have never done it on any car I have ever owned befiore. I'm going to wait until it's at least 32 degrees though. I did change my transmission fluid for the first time the last time I changed the oil in the wagon.

 

Well, I don't connect the jumper cable to the battery negative because I know the battery acid fumes can explode with the spark, but his post did make me feel a bit stupid. I don't change my tranny fluid or brake fluid, or know how to clean the PCV, throttle body, disassemble the fuel rail, check injectors or valve guides. But being an embeddedsoftware developer, and I like to tackle difficult problems and learn.

If I had the money I'd probably just have a Mercedes and change it every four years, taking it to the stealership. But since I don't I have to protect myself from most rip-off mechanics and stealerships here, giving my family the best safety my small budget can afford.

It's incredible how very smart people I know buy new cars that are have such thin doors and are very light and small. I don't even what will happen to the passengers of that vehicle in case of an accident. We live in the suburbs, close to a high speed highway. Porsches, Mercedes, Audis and BMWs are very common here doing 200 km/h, while the speed limit is 130. On top of that the road is full of old cars too and retarded drivers. I mean drivers thatdo 80 on the 130 lane or 160 on the 80 lane, basically zigzagging like they were playing on a Playstation. Chances of an accident are very high here, so I don't understand why so many people buy cars that are so unsafe and, on top of it, very expensive in comparison to my 850.

Wehave great weather, I love that here. No snow, no tornados, no floods, no earthquakes, no volcanos, no hurricanes or tsunamis. Great women, great food, cheap prices, and mostly European genetics. Too bad we have very corrupt politicians, judgesand policemen.

 

We have tornado's here had some the other night.
Only about 15-20 miles from my house.
Wiped out over 1000 homes and killed 19 people.

 

Hi Jim,

Please don't feel bad, to this day I do not know a technician who knew everything. As to the brake fluid, it is ok as long as you don't do repeated hard brakings in hot weather/steep downgrade, and as long as the brake pedal feels firm. But it does absorb moisture over the years, and considering you & your family's safety, I would change it at least once every 3years. If you plan to do it yourself, you would either need an assistant (your son-in-law?)or one-person bleeder, such as Motive Products' European Bleeder (Approx. $50). You probably know, that Volvo uses DOT-4, not 3.

As for the tranny fluid, some mfg's say it is good for the life of the car. If the fluid is still clear red and doesn't have burnt smell to it, it is ok not to change it. But I believe it is good to replace it every 30,000-40,000 miles or 3-4 years, though not replacing it probably wouldn't hurt anything, unless it has discolourationor burnt smell.

As for the battery connection, some people have gone permanently blind, as they connected the negative cable directly to another battery and it exploded as a result of spark that ignited hydrogen fumes coming from the battery. This is more so with older batteries, as they seem to produce more hydrogen fumes. I know some people think I'm stupid, but I always wear eye protection when I service my battery. You can connect the negative cable to any bare metal in the engine compartment of the car with dead battery. I usually use engine itself, as far away from the battery as possible.

BRAKE FLUID REPLACEMENT:
Some say you need to bleed master cylinder but I never do it. If you want to, you can pressurize the system (either by an assistant pressing on the pedal or by one-person pressure bleeder) and loosen flare-nut on the bottom of the master cylinder, let the fluid drip until you think is enough.

REQUIRED SUPPLY & TOOLS:
1. An assistant or One-Person Pressure Bleeder.
2. 2 quarts of DOT-4 fluid, from sealed container.
3. 6-point deep socket.
4. Flare-nut or open-end wrench.
5. Clear glass jar (the bigger the better but not too tall, I generally use salad-dressing jars).
6. Clear plastic hose/tube, about a foot or two.
7. Rag (brake fluid is alcohol-based, and it eats up the paint).

PROCEDURE:
In general, the correct bleeding sequence is to start from the wheel that is further away from the master cylinder (right-rear wheel with left-hand steering). So, the sequence is:
1. Right Rear
2. Left Rear
3. Right Front
4. Left Front

a. Remove some fluid from the reservoir and fill with clean fluid.

b. Pressurize the system, either by an assistant or pressure bleeder. If using an assistant, put the cap back on. Keep an eye on the fluid level and keep it at theMAX line.

c. Loosen the bleeder screw on calipers with 6-point deep socket, about one-turn, attach a clear tube (available at hardware store) onto the bleeder screw, guiding the other end into a clear glass jar. Loosen the bleeder screw with open-end wrench, flare-nut wrench or finger until fluid starts flowing into the jar. You will see tiny air bubbles and some gunks, and keep bleeding until you see no more bubbles. Tighten the bleeder screw just to a snug or to specified torque. Repeat the same for all wheels. When done, check the fluid level in the reservoir and add just a hair below MAX line. If the pads are new, you can fill it up to the MAX line.

d. Test the brakes to make sure thatthe pedaldoesn't not feel spongy. Test drive, on a deserted road, at low speed (10-20 mph will do) and test the brakes. It may require a few pumping sometimes to restore hard pedal feel. If the brakes feel weak, stop the car (with parking brake if necessary) and repeat the above procedure, until you're 100% sure there is no air in the system.

*Someone please correct me if I omitted something here.


Hi Axel,

I also am not sure how to service PCV system on 850, as it is much different from other makes where you can just replace the PCV valve & breather filter. I somehow knew you work in theIT industry, as I noticed the use of "protocol", "Baud rate", etc... You might want to invest under U.S. $20in a Haynes manual. As to cleaning the throttle body, I usually disconnect the induction hose, spray throttle cleaner into the throttle plate, opening & closing the butterfly valveby hand, and scrub clean carbon sludges with tooth brush. I then start the engine and spray the cleaner by opening the throttlejust enough not to let it die while I spray the stuff. M. Tech would be more through & exact, I believe.

Mercedes and BMW seem to be maintenance nightmare, especially with electronic systems. This is one of the reasons why some of their customers switched to Lexus. Well, it doesn't really matter to me as I couldn't afford any of them, unless used (or "Pre-owned" or "Re-conditioned"). Considering overall package with safety being the priority, I think Volvos are the best, I only wish Volvo designed better electronic systems.

>mostly European genetics.
Mostly German descendants, I believe?

>Too bad we have very corrupt politicians, judgesand policemen.
It's universal. All of them are after $$$.


M. Tech:
May I suggest that you move to Chicago, it's nice up here, just horrible drivers and single-digit winter. But note that the official language is either Spanish or Polish in Chicago[8D].

Good weekend to All,


JPN

 

No thank you I lived in N.J. the first 21 years of my life and it is only nice to go back and visit.

Fla is alot better and weather nicer.

 

Sorry to hear that. I know several people who live in FL and they are always complaining about the storms and tornados. But I still love Miami. Every time I go there I don't even need to speak English, ene though I like to practive. I guess most people only speak Spanish there. It's like a clean Latin America.

 

We are in a state of Emergancy here.
Thank god all was fine here at my house. But I always thing next time could be us.

 

I downloaded a scanned one using eMule. The shipping to Argentina would cost way too much. I also have VADIS and Service Manuals.

Mostly Spaniard and Italians. That's why the country is so corrupt, like all the other Spanish-descending countries. I have German nationality also, my wife has Argentine and Spaniard, and my daughter was born in Brasil when I was transferred there by my former employer.

We teach your politicians how to steal here. It's probably one of our main exports along with excellent meat, petroleum and cereals.

You gotta be kidding. My mom just moved from Oakland Illinois to Argentina and she was always complaining about the snow and the tornados.

Regards
Axel

 

Send me some of the Great Women and I won't worry about the cold.

 

I donĀ“t even know what it is for, much less fix it and I'm too lazy to check in wikipedia

Why are the electrical connectors all green and corroded? IĀ“ve never seen that before in cars. Is that fixes in modern Volvos or do they still save 5 dollars per harness on the anti-corrossion treatment?

 

Hi All,

>No thank you I lived in N.J. the first 21 years of my life and it is only nice to go back and visit.
>Fla is alot better and weather nicer.

Come on Tech, don't you miss good old Garden State? Harsh winter, traffic jams, expensive toll ways Fla must be nice, but I myself probably couldn't live there even if I could, not having snow in winter for me is a crime[8D]

>Mostly Spaniard and Italians. That's why the country is so corrupt, like all the other Spanish-descending countries.

How ignorant I was. I just remembered that there was one country in South America where there was a lot of German descendants. Not to worry about corruption, Japanese are as bad. That country is going downhill fast, and I am not looking forward to going back.

>You gotta be kidding.
Yes, I was I'll be leaving Chicago later this month and am relieved. Not my kind of place to live.

PCV system is used to relieve the crankcase of pressure build-up due to blow-by gas past piston rings, etc... So, the system is usually located between the crankcase and intake system.

>Why are the electrical connectors all green and corroded?
Here's my theory. In Sweden, winter is very long and people long for Spring. Green isthe symbol for Spring, the grass field, flower gardens, trees, etc... So, Volvo engineers & technicians needed some sort of mental-support so that they can do their best in creating/maintaining the most robust passenger cars on Earth. "All right, OBD-II diagnosed, 4 more months till Spring!!" What else could be more motivating than green connectors?

Also, since Scandinavian nations are noted for being "environmentally friendly", they symbolized green as their effort toward clean air, trying to remind Volvo drivers to be enviro-friendly as well...Imagine if Volvo produced totally-renewed 850 in deep, rich green paint, it'll become an instant hit!

...pretty lame assumption, hun?

As to corrosion, the stealership needs to make money once a while for not much of a reason....[8D]

Good weekend to All,


JPN

 

Jim,

Replacing brake fluid is just the same as bleeding it except you do it for a longer period. You'll notice a difference in the color of the fluid even without using a fluid with dye in it such as ATE Super Blue.
[align=left] [/align]

 

The last car I even remember bleeding the brakes on was a 66 Karman Ghia. I have never needed to bleed the brakes on any of my Volvo's and they have all alway braked just fine.