Hey, Aidan.

Since nobody else has touched on them, I want to make these 2 points:

First - Aside from Vented vs Solid (one has a hollow center to keep it much cooler), all of the slotted and drilled rotors are gimmicks and work to reduce braking performance and mostly the money in your pocket. Avoid them all.
Vented or solid is pre-determined for your vehicle unless you want to go to some lengths to convert from one to the other.

I don't know what Napa you went to, but I worked for one and there was no such thing as a "service charge" unless you mean the labor to install them. $4350 is high. You could buy new calipers, rotors, pads, hoses, fluid, and brake parts cleaner for about that price. Maybe a master cylinder if there was a sale.

Rotors will generally cost you $40-65 each locally. Don't pay more than that. You can find them for $25-40 each online, but the shipping cost makes it kind of pointless.



Pads can be had for a song through mail order. I can see a dozen for under $15 a set (both sides of one axle) on Rockauto.com right now. The same set going for $15 will run you $65 in a store. The problem with buying online is that most manufacturers won't show the friction rating in their photos for some reason I can't figure out.


Second - Pads all come with a Friction Range Rating with 2 letters. You can skip the next 3 paragraphs and buy FF rated "semi-metal/metallic" pads if you want to take my advice at face value. The 2 letters are a friction coefficient measured in a standardized test under "normal/cool" and "stressed/hot" temperatures. The friction grades have no overlap but have wide ranges. The grades are E, F, G, and H. I've never seen an H pad for a Volvo. Most pads will be either E or F. My personal preference is to get pads that have two of the same letter. Pads that are different letters might have been on a cusp (you can look up the values, but a 0.01 difference in friction coefficient can move a pad to the next rating), but generally speaking, it's a Bad Thing in my mind because they are inconsistent. Pads that go up (EF,FG) a letter are probably the type I have to mash the pedal when cold (on the highway and someone cuts me off) but that grab progressively harder when I'm coming to a stop at a light. Pads that go down a letter (FE, GF) are probably grabby at first but then almost slick on steep hills and mountain roads. Everybody likes something different though. I even had a girlfriend complain that her brakes worked too well.

My take on "pad materials" is this: Organics are weak and bad when hot but kind of easy on rotors, ceramics (especially cheap ones) are overpriced and have all the bad properties of organics plus tend to ("warp") wear rotors unevenly, and semi-metal pads are the best balance of all possible things for a daily driver even if you get the cheapest one in this category.

The truth is that there is no established definition of what pad material actually is (organic, semi-metallic, ceramic, and even sintered and semi-sintered for motorcycles). They are all marketing terms for proprietary blends of this and that plus a healthy dose of glues/resins that do a large part of the braking. Most counter-jockeys will try to sell you ceramic pads because someone wrote "OE is ceramic" in the database for literally every single car they have info for and a ceramic pad to sell you. "Ceramic" is a term invented around 1998, so anyone who claims this is OE for your car is full of beans and maybe some other things.


At any rate, doing brakes is not beyond you. Read the FAQ. Read all the FAQ "oops" things. Get your parts together. Grease the caliper pins (if any) and not the rotors, bleed the brakes (don't ruin your master cylinder), and "bed in" your brakes properly for best results.

Happy Bricking! (And braking hopefully)
William

If you are changing rotors, you should consider changing the emergency brake shoes as well.

At the very least, you should take the emergency brake assembly apart and evaluate the condition of the parts, including the cables and the pivot on the rear axle if there is one,

The rear axle pivot rusted off on one of out 740s. I was able to fabricate a new pivot out of a farm hinge and a U clamp from a muffler to hold the pivot to the axle.

Emergency brake shoes that fall can disable your car.

Working on the emergency brake shoes looks difficult, but it is only a bit fiddler.

All 240 series cars have disc brakes in the rear with provision for an internally machined "drum" for the parking brake shoes to rub against. Don't bother with the extra expense of drilled or slotted rotors unless you plan on racing or only driving down mountains - and even then their effectiveness is dubious. Quality of materials can vary so careful research or trustworthy recommendations are called for, as you have realized. I haven't had any recent experience shopping for such items so do not have any specific recommendations as far as product quality goes. -- Dave