2000 V70R - AWD Broken bumper mount bolt

Post by **scot850** » 01 Sep 2015, 21:46

I decided, that it was time to look at removing the rear bumper to fit the powder coated bumper mounts. I am aware the bolts can rust, but thought I was lucky as the first one came out relatively easily, so I removed it, cleaned the rust of it (it showed signs of heavy pitting near the bolt head), put anti-seize on it and replaced it for now. RH side does not have the same access to get in with Deep Creep. I did get some in there and let it sit. When I tried to remove it, the head immediately snapped off with about 1/2" of the shaft. This of course means you cannot now remove the bumper as Volvo have fully enclosed the bolt. so no access to somehow remove the rest of the broken bolt.

Has anyone come across this before (can't believe no on has) and know how to get around this?

Looking at the bumper drawings, can you remove the plastic cover, and the foam buffer to get to the aluminum stiffener? If you can, I could drill the bolt out or grind the captive nut off the top of the bracket to allow removal if this can work?

Input gratefully appreciated!

Neil.

Post by **scot850** » 02 Sep 2015, 22:16

I was at PnP today and decided to look at a bumper on a V70 XC that was there. Of course the 2 bolts came out without any real difficulty. From what I can see there is no way to remove the rear bumper without removing the bolt first. The bolt runs up through a round stiffener sleeve, so there is no way to get any Deep Creep to it any way if you have a rusted bolt. I had hoped the plastic sleeve could be removed giving access, but it is screwed to the bumper stiffener from the back. Only thing I can think of is to bend or cut the lower flange of the bumper mounting bracket to allow possibly for the bumper to fall off the bolt.

Surely I can't be the only one that has hit this issue? Anyone?

Neil.

Post by **scot850** » 03 Sep 2015, 22:48

Still no help on this? Looking at the scrap car I took apart at PnP yesterday, I think my plan may be the only way. A bit of brute force applied after bending down the lower flap on the offending bracket. The brute force is to bend the remaining part of the bolts (hopefully) outward sufficiently to allow the bumper to drop down. I'll get back to this eventually.

Neil.

Post by **scot850** » 04 Sep 2015, 16:43

Even the dealer couldn't answer this one!

Fortunately I have a friend in Germany who has told me my version of bending the bracket is considered the standard on the forums over there.

Neil.

Post by **scot850** » 07 Sep 2015, 18:00

In the absence of any real help on how to tackle this problem, I took some after the event pictures to try to show how to remove the rear bumper after a mounting bolt had sheared leaving the majority of the long shaft stuck in a narrow tube with no access to remove it.

Although I did get little guidance on this, I must back up and say 2 members did help give me the confidence to stop procrastinating and bite the bullet to get it done. Also a PnP visit to remove a bumper showed me how it all goes together to try to minimise and physical damage to parts I am not replacing.

So a big thanks to one of European friends who gave the advice on bending the lower lip of the mounting brackets to give a better chance of removing the bumper un-scathed (you know who you are!), and also Robert (rspi) and his marvelous video on how to remove a non-challenged bumper. A worthwhile watch if you have ever a need to tackle this.

I had a long think about this and was getting stressed as there is no easy way to access the bolts once they break, and possibly a large chance of seriously damaging the bumper or the cover. I took the sage old advice and cleaned the bracket mounting bolt threads that can be viewed and soaked them in Deep Creep over a few visits and several days.

I had already been successful in removing one of the 2 through bolts that hold the rear bumper to the mounting brackets. Below are a couple of pictures on the bolts. Note the condition of the broken bolt. This is again caused by electrolytic corrosion between the bolt and the aluminum stiffener.

: Rear bumper through bolts (1)

: Rear bumper through bolts (2)

The problem of the broken bolt is that you cannot slide the bumper out of the bracket with the broken portion still in place. I had hoped that by bending the lower flange of the bracket down vertical, there would be enough room to bend the bolt out while levering the bumper from the back. The problem was I found I could not easily dis-engage the side mounts on the bumper as they fit in a slot and again you need the bumper to slide straight back to dis-engage them.

: Side bracket on a V70 rear bumper

: Side bracket on a V70 rear bumper (2)

The above picture tries to show the 2 slides that the bumper slide into.

: Side bracket on bumper itself

This tries to show the 2 corresponding slides actually on the bumper with the 'hooked sections I did not want to break off.

Now I'll show how the brackets actually mount on the car and the bumper:

: Rear bumper mounting bolts 2 per bracket

These are the 2 bracket bolts for each of the brackets to mount to the car. Note the domed ends on them to make easier to align into the captured nuts.

: Rear mount for rear bumper bracket

Above picture shows the mounting on the rear of the car. The left side is slightly bent thanks to a hit and run driver in a parking lot.

: Rear bumper bracket in place

Above is the bracket loosely mounted. I have put the bolt retaining long bolt so you can see where it locks the bumper top and bottom.

: Side view of rear bumper bracket

From this picture you can see that the bolt and bracket cannot be accessed from above as the rear hatch has a flange that completely covers it from above. This flange also prevents just pulling the bumper down to clear the broken bolt.

: View from under the bumper bracket

: Bumper stiffener

You can see in the picture above, the aluminum bumper stiffener. The single hole to the right face, is the through hole for the long mounting bolt. The 2 lower holes on the left actually are dimples that hide access to the bumper mounting bracket bolts.

: Bumper stiffener (2)

This is viewed as looking toward the back of the car.

So having looked the job over, my first action was to support the bumper, and then remove the 'good' bolt. I still needed to use a pry bar to leaver the bumper stiffener out from the 'good' side.

I drilled out the rivets from the wheel arch:

: Holes for rivets

You need to remove/drill out 3 rivets and remove a T25/T30 (?) screw through the top of the bumper edge, and remove the mud-flaps. This now releases the bumper sides to slide rearwards. Actually I did this first, before levering out the good side bracket.

Next, I needed to fold the lower edge of the bracket with the broken bolt in it:

: Folded down lower bracket edge

This then gave me room to try to force the broken bracket through bolt to move the bumper out. As the bracket was so rotten, it allowed me to actually move the bumper stiffener out enough to get to the 2 bracket mounting bolts with a 14mm ring wrench. I worked the 2 bolts out a bit at a time and wound them in/out and wire brushed and Deep Creeped them constantly until they eventually came out. I also used the open end of the wrench to get better access.

This allowed me to be able to remove the whole bumper and the bracket.

With the bumper now safely on the ground you can access the bracket and a gentle 'nudge' with a hammer allowed the bolt and bracket to slide up and out of the top of the bumper stiffener.

Bumper safely removed and the rotten brackets removed without damage to the bumper or car!

Why not remove the cover first? The rear cover is screwed to the top of the stiffener by about 10-12 screws that go though holes in a lip on the top edge of the bumper cover and sandwich the bumper cover in place. Levering up the bumper cover will break all these off. They are also hidden behind a glued on rubber seal. All this is hidden under the lower lip flange of the lower rear hatch opening.

: Retaining screws for outer cover

Hopefully this is of help to others that will get into this position.

A point of note is that you will see how corroded the bumper stiffener is in the area where it touches the mounting bracket. I have seen stiffeners that are actually rotten through at this point! If you are brave enough, you may want to consider removing the mounting bolts from time to time, and use anti-seize. I am also planning to use a strip of 3M hood/paint protection as a sleeve between the stiffener and bracket to try to prevent further reaction.

Neil.

Post by **scot850** » 07 Sep 2015, 22:59

Thought I should change the title as I have no completed the fix for the problem and have removed the rear bumper safely.

Neil

Post by **erikv11** » 08 Sep 2015, 09:02

I had to do something like this to replace those mounts on my 95 850, due to a sheared long bolt. I don't remember details of what I did, just that it involved bending disintegrating metal, cursing, and finally disassembling that side after dropping the bumper. Luckily it was such a rusty mess it was not too difficult to force. Excellent documentation.

Post by **scot850** » 08 Sep 2015, 17:11

Thanks Erik.

Thought I's add a small addendum. I lied about the screws holding the top cover on. While I still believe it would not be easily possible to get to them to undo, careful prying up of the upper cover lip may allow access with a long Torx (T30/35?) bit, but you would be unable to get it square. A Torx wrench (like an Allan wrench) might be able to do it but you would be working blind, and a high probability of damage to the top of the bumper cover rear lip. The 'R' rear cover is slightly different to the standard wagon so there may be a difference in access to this. A sedan would be very difficult to access.

: Top corner of rear bumper

: Hidden mounting bolts for rear bumper cover

You can see one of the bolts hidden here under the lip. There are 9 bolts on my cars bumper all along this top edge. They do not go around the curve under the rear lights.

Neil.