Brake shudder at highway speeds

[Kiwirst]

Hi,

As this is my first XC70, I'm not sure how the brakes are meant to be.

I feel like the pedal is a little soft and long, but the other issue I feel is at highway speeds when I brake, I feel a shudder but I don't have any steering wheel vibration that would indicate warped rotors.

It doesn't happen at lower speeds. Pedal softness/length is the same at low & high speeds.

[albertj]

Your brakes although probably not unsafe, are likely worn.

If you have a caliper check the rotor thickness.

If you come across a good deal on rotors & pads, buy and schedule yourself for doing the brake work some fine temperate day. If you do the work yourself it's less expensive and you need not try for "perfect" timing waiting for the current brakes to wear further.

I consider my brakes candidates for replacement when worn down to the bottom of the groove cut in the pad face, or if there was no such groove then the base of the chamfer at the leading/trailing edges of the pads; if neither chamfer nor groove then 1-2mm of pad remaining. Be sure to check both sides and go by the thinnest, and if they wore unevenly then you need to service or replace the calipers as well as the pads/rotors.

If you can put one foot on the floorboard under the brake pedal and when stepping on the brake pedal with the other foot, touch the one on the floorboard, then inspect/service the brakes immediately. Brakes are the most important system on a car, and pretty much (https://en.wikipedia.org/wiki/Vehicle_inspection_in_the_United_States)every state inspection regime checks brakes.

[Kiwirst]

Interesting, I had the car serviced by a Volvo workshop (good reviews from customers) and they said the brakes were ok.

I will keep an eye out for good front & rear deals, I have seen a Front/Rear Slotted/ Drilled pack with ceramic pads for $125 on eBay.

[AutosDirectFlorida]

Dont Ebay these parts unless you know exactly what you're getting - Check RockAuto for some comparisons and their prices are usually pretty good too.

[AKAMick]

First thing is pull both wheels and look at the brakes, cant tell anything until you do that, after a drive touch both calipers with your finger if one burns your finger you have a frozen caliper, then it has to be replaced

[hoonk]

at highway speeds when I brake, I feel a shudder but I don't have any steering wheel vibration

That is a description of rear brake rotor problems. Some may call them warped, and they might be but usually rusted areas (discs rust on a car that has sat for a long time except under the pads and cause a "rumble") - or areas where friction is different cause your symptoms.

[JRL]

You need rotors.
If the steering wheel is shaking on braking, it's the fronts. If the entire car shakes more or like from underneath, you need new rear rotors.
Always install new pads when installing new rotors.
Got all these parts installed, BLEED them properly and it will brake like a new car.
If you can afford it now do all four with new pads and rotors. I prefer Akebono Euro ceramics for pads, no brake dust. They will brake like stock pads, no better, no worse but NO BRAKE DUST to deal with! For rotors there are several good rotors available that work well with Volvo. Just don't use the cheapest, just not worth it but any decent mid grade will be fine

[albertj]

+1 on what AutosDirectFlorida said. Even if it's just to learn something of the scope of what's available, have a look at rockauto.com. Also have a look at ipdusa.com, autohausaz.com and fcp.com -- they have an interest in selling to Volvo owners and instead of presenting a very wide selection of parts that will fit (rockauto.com) they each present a more limited selection that in their experience are better quality for enthusiasts.

Your brakes were OK the day they were checked and would likely be OK for a while after. HOWEVER, Brakes don't wear directly by time or mileage, rather they wear by the number of times you stop the car, modulated by the speed driven (how much energy the brakes have to dissipate as heat in order to stop the car) and the manner in which stopped. The materials and mechanicals may bind or fail from wear, disuse or abuse. Things I've seen include caliper pistons that bind and make the brakes drag; slide pins that warp (rare) or that corrode due to owners not being aware that the boots are gone or compromised for some reason; slide pins that bind due to lack of proper lubrication (most frequent).

Concerning brakes -- over time I've found that the least expensive way to maintain a car well, if you can do it, is to use OE or better parts and do the work yourself. Lemforder and Ate, for instance, are European OEMs for various manufacturers. Wagner (Federal Mogul) and Bendix (Honeywell) come to mind for others. I also note that OEM-line parts for the XC70 brakes are not terribly expensive, although not free of charge either.

Bottom line for me, I think AKAMick is on the right track advising you check them yourself, but I would not use a finger; Really, just set aside some time one day soon and have a look for yourself. And not just thru the alloy wheel openings, pull the wheel so you can get your head in there and look at both sides easily, as well as thru the inspection hole on top of the caliper to determine if the wear is uneven... Still unsure? Post some cell phone shots of the brakes. Could be something else, like the antirattle springs are on wrong. JRL may be right concerning you needing rotors, however the cause may be (a) rotors were already at the wear limit last time new pads were put on, and they heated and warped. This happens with the $50 or so -per-axle brake jobs especially when someone's already put on economy-grade rotors. Inexpensive rotors are notorious for warping, and you can usually see the warp if you pull the rotor hat and just look at it from the side. or just measure the runout with a runout gauge. On better rotors, which measure within runout allowance of say 0.003" or so, what sometimes feels like warp is that after a pad replacement the pad compounds were different on the new brakes, and did not lay down evenly on the rotor (one hard stop can do this). Unless you can resurface or turn the rotors as needed, you'll need new ones. And if the ones you have were "economy" rotors to begin with, they are not likely worth turning in any event because part of how they make them cheaper is by making them thinner to begin with.

If you are going to look for something on eBay, look for a dial caliper and a runout gauge with magnetic stand. The ones you find will not be good enough for research & development, but will be good enough for you as handyman to check brakes. Your figure of merit is 0.001" which corresponds to 0.02 mm. Dial indicators (digital or analog) claiming 0.0005" resolution are $5.00 and up on eBay, however they are not calibrated and so technically are "comparators." And their guts can be goofed up with one drop of any significant distance. That said, using one comparator on a brake job will give you measurements good enough for this work since the indicator's precision is more than adequate and you're comparing it's measurements to the same indicator's other measurements. Your issue actually is going to be the quality of the base. I actually use a base welded to a ViseGrip(TM) brand locking plier. It's not going anywhere once I lock it down on something solid. A dial indicator along with vise grip as a set will set you back $35 to $70 on FleaBay.

The only remaining problem, which as a handyman you can't fix unless very well equipped, is lathing the brake rotors on-the-car. That said, if you are very careful, getting the rust off the hub face with a Scotchbrite pad or some such, and you DON'T buy crap parts, usually you can get away without lathing the rotors on the car - your runout would be likely be less than 0.004". Such lathes however are not cheap. Unless you luck up on one at a dealer or garage liquidation auction and it's not rcognized for what it is, you will pay $hundreds to get one. But that's why you want a dial gauge; if you have a runout problem it's easier to fix when you are doing the brake job in the first place, and you can sometimes (umm... often) fix it enough by merely re-positioning the rotor. The OE-style rotors for the XC70 have little holes where the Volvo index pin goes thru. Just put the rotor on the hub, snug up a couple opposing hub bolts to hold it on, then check runout. If you measure any (you may not find any) then move the rotor one bolt position clockwise, re-secure and try again. When you have minimized runout, what you do is make a mark (strike or scribe) by that index pin hole, so you know how to position that rotor on that hub (because you now have to take it off and button up the job) if a wheel service goes that deep in the future for some reason. On my other car with no index pin I just use a permanent marker to tag one lug and it's mated hole.

There's a decent article about servicing disk brakes at this LINK (http://www.knowyourparts.com/technical-resources/brakes-and-brake-components/brake-rotor-service-tips/), if you have read this far and have time on your hands.

[Kiwirst]

Albertj - Thanks for the information, very valuable. Distilling all of this information down, I am getting to the point where I need to invest in new rotors and pads (longer term invest vs trying to machine out any issues, which may or may not solve the issue and lead to more work).

On the fence about performing the work myself as I have limited time most weekends due to a 2 year old and all the other weekend related work although, my last experience of a pad change by Brakes Plus nearly had me in an accident after a 35 mile drive home and the pedal goes to the floor!

Looking at Autozone (I can get free stuff through work for them) I have some options, knowing how good Brembo is I'm tempted to go with them however the pads to match push the price up significantly.

Update: Duralast Gold Rotors & Pads vs IMC Brembo Rotors & Pads? Cost is roughly $30 between them, anyone have any input on this?

[JRL]

Brembo sells at least three different rotors in price and quality, perhaps four
As I said whatever brand you buy, at least go with their mid grade or better, do not use the lowest price rotors, that's just asking for trouble!
AWD Volvos tend to use up REAR rotors quite quickly. Why, who knows, but I've had them go bad in as little as 10K miles on a new car!

As said, if you want to get rid of the brake dust, use Akebono Euro Ceramic pads, no dust!. They work about the same as stock pads work and are priced about the same.
Everyone is now selling them so easy to find.

[Kiwirst]

Thanks,

I'm trying to purchase all this through the best avenues and I think I'll go with the Brembo rotors & Akebono pads as suggested.

Any advice on what tools I should use and tips to make this a painless swap? Do I need caliper press to push the cylinder back or does taking the reservoir cap allow for hand pushing if more space is needed?

Downloaded & printed the helpful pdf's for the car someone put up in an earlier link on another similar thread.

[Scopeman]

To compress the caliper a large C clamp works fine.
If you are doing the rears as well, you should consider replacing the parking brake lining and hardware while they are apart.
Make sure to note how the anti-rattle springs are installed. It is easy to reinstall wrong. Be careful not to bend the soft aluminum backing plates.
A pressure bleeder makes that job much easier, and don't get brake fluid on the paint!

[albertj]

Brembo sells at least three different rotors in price and quality, perhaps four
As I said whatever brand you buy, at least go with their mid grade or better, do not use the lowest price rotors, that's just asking for trouble!
AWD Volvos tend to use up REAR rotors quite quickly. Why, who knows, but I've had them go bad in as little as 10K miles on a new car!

As said, if you want to get rid of the brake dust, use Akebono Euro Ceramic pads, no dust!. They work about the same as stock pads work and are priced about the same.
Everyone is now selling them so easy to find.

+1 on all this.

I have some ideas about the rears but not sure yet.

[Xfingers]

I also used a C-clamp to compress the calipers. Maybe a little bit cumbersome or awkward but it worked. I had to buy a hex driver socket set, specifically the H7 socket (7mm), to loosen the locating pins (underneath the rubber dust caps) in the caliper pistons.
Tutorial from the Resources section: http://www.volvoxc.com/0/resources/how-to/pdf/xc_front_brake_pad_replacement.pdf

[albertj]

About the rears, I don't know... I don't know how the front/rear proportioning valve is set, I don't know how "hard" the OE spec pads are front vs. rear, and I don't know if/how those factors get modified as people work on/have work done on their cars.