DIY Rear Bumper Bracket Repair: 1997 Volvo 855 GLT

[jreed]

Our 1997 Volvo 855 GLT wagon was recently hit on the rear bumper. I took the rear bumper off and replaced the brackets, bolts and washers and I took some photos along the way to show what I did in case it might be of use to somebody else faced with a similar project. As others have noted, there was a great deal of corrosion on the passenger side bracket, which explained the large amount of downwards sagging after what was a relatively minor bump.

Before starting the work I searched MVS and found this helpful thread:
https://www.matthewsvolvosite.com/forums ... =1&t=48292

Here is what the car looked like at the start of the project, with the rear bumper sagging downwards after having been hit:

Rear bumper after having been hit, showing sag.

1) Bumper after getting hit.jpg (83.46 KiB) Viewed 11896 times

Here are the parts I used to make the repair:
Two new brackets (part #6816114):

Bumper brackets for 850

0) New bumper bracket part number 6816114.jpg (88.75 KiB) Viewed 11896 times

Two new long bracket-to-bumper bolts and washers (part numbers 973096 and 960143):

Long bolts and washers holding the bumper to the brackets

0) New bumper bracket, bracket-to-bumper bolts and washers.jpg (57.12 KiB) Viewed 11896 times

Four new bracket to car frame bolts and washers (part numbers 985191 and 986527) (note: the yellow plastic washers are not needed):

Short bolts and washers for holding bracket to car frame.

0) Replacement bracket-to-frame bolts and washers.jpg (46.79 KiB) Viewed 11896 times

Before starting the work, I also consulted the VADIS database, which had the part numbers for the brackets and bolts. I took some screenshots of the database. This one below shows the part numbers for the long bolts (973096) and washers (960143).

VADIS rear bumper parts diagram

There was also an abbreviated set of instructions in VADIS for how to remove the bumper:

Abbreviated instructions from VADIS on rear bumper removal.

0) V-850-rear-bumper-VADIS2.gif (96.57 KiB) Viewed 11896 times

Making the repair--
The first thing I did was to remove the tailpipe:

After loosening the 10mm nut to allow the tailpipe to be slid off of exhaust pipe.

2) Removing the tailpipe.jpg (121.78 KiB) Viewed 11896 times

Then, I went inside the car to remove the decking in the back on the driver's side of the car:

4) Remove decking.jpg (108.95 KiB) Viewed 11896 times

Then (again on the driver's side) I lifted the flap in the sound-proofing to expose the 10mm bolt head:

5) Lift flap to expose 10mm bolt.jpg (83.74 KiB) Viewed 11896 times

Next I loosened the bolt:

6) Loosen 10mm bolt.jpg (92.39 KiB) Viewed 11896 times

Next on the passenger's side of the car I went underneath and found the 10mm bolt (note how difficult it is to see):

7) Camouflaged 10mm bolt on passenger's side.jpg (150.66 KiB) Viewed 11896 times

I cleaned it up:

7) Locate 10mm bolt on passenger's side.jpg (89 KiB) Viewed 11896 times

Blasted it with P'Blaster (my favorite bolt-freer):

8) P'Blast 10mm bolt on passenger's side.jpg (88.34 KiB) Viewed 11896 times

And removed it with a ratchet:

9) Remove 10mm bolt on passenger's side.jpg (103.09 KiB) Viewed 11896 times

Next I turned to the rivets (three on each side) located on the wheel well:

10) Rivets in wheel well.jpg (71.65 KiB) Viewed 11896 times

I drilled the rivet heads to allow them to be cut with pliers later:

11) Drilling heads of rivets.jpg (105.47 KiB) Viewed 11896 times

Then I nibbled the heads with cutting pliers:

12) Nibbling heads of rivets with pliers.jpg (71.74 KiB) Viewed 11896 times

And more nibbling:

13) More nibbling on the heads of the rivets.jpg (96.24 KiB) Viewed 11896 times

Contrary to my expectation, the rivets were made of aluminum with a black coating. I was expecting plastic rivets but I guess the plastic rivets are the new replacement style and the original rivets were aluminum.

Aluminum rivets with a black coating

14) The rivets are aluminum with black coating.jpg (134.16 KiB) Viewed 11896 times

At this point with the 10mm bolts loose and the rivets cut, the bumper wings will be free to be pulled away a little bit from the sides of the car body.

15) The bumper wings come loose from the body.jpg (86.63 KiB) Viewed 11896 times

There are two (one on each side) metal slip bolts that are held in plastic slots inside the wings. I removed them for safekeeping at this point:

16) Catch or remove the slip-bolt inside the wing.jpg (91.63 KiB) Viewed 11896 times

The next step is to remove the long vertical bolts that hold the bumper to the brackets. I'm going to write up that segment of the repair in a second post.

[jreed]

Next up is removal of the two long vertical bolts that hold the bracket to the bumper. The original bolts had 14mm heads but the new bolts had 13mm heads.

17) Loosening bumper bracket bolt.jpg (136.22 KiB) Viewed 11893 times

On the passenger's side, when I loosened the bolt some water dripped out, so keep your face to one side when loosening that one:

17) Withdrawing wet bumper bracket bolt on passenger's side.jpg (112.61 KiB) Viewed 11893 times

There was a great deal of rust and pitting on the bolts and washers so I'm glad I replaced them with new:

18) Withdrawing pitted bumper bracket bolt on driver's side.jpg (114.03 KiB) Viewed 11893 times

The original bolts had an interesting cross-thread cut that I guess is to make it easier to extract when corroded:

19) Corrosion on bumper bracket bolt (note cross thread slotting).jpg (101.25 KiB) Viewed 11893 times

The new bolts don't have this feature.

Once you have removed the two vertical bolts, the bumper is ready to slide out and off. Just pull it straight back from the car and set it on the ground. It is not heavy (maybe 20 lbs?).

Next, you have to remove the brackets. The passenger side bracket on my car was in a sorry state of corrosion -- almost completely rusted through:

20) Nearly complete corrosion on bumper bracket.jpg (150.43 KiB) Viewed 11893 times

On each bracket, loosen the two 13mm bolts holding the bracket to the frame of the car:

21) Loosen the two 13mm bumper bracket bolts .jpg (111.05 KiB) Viewed 11893 times

And remove the bracket to reveal the frame attachment point:

21) Remove the bumper bracket .jpg (119.33 KiB) Viewed 11893 times

I had to straighten out one of the ears of the driver's side attachment point:

The "Commander" -- a pair of 16" slip-joint pliers, my favorite

23) Straightening the bracket face with my ''commander''.jpg (123.83 KiB) Viewed 11893 times

Next, since I had the bumper off, I decided it would be an opportune time to paint the black bumper plastic. I used some brake cleaner to remove oil and grease and a little 320 grit sandpaper to roughen the surface first. Here I've masked off the area to be painted:

22) Preparing the bumper for black bumper paint .jpg (167.57 KiB) Viewed 11893 times

After the first coat of flexible black bumper paint (Duplicolor FB105):

22) First coat of black bumper paint .jpg (148.15 KiB) Viewed 11893 times

Back to the car, I installed the new bumper brackets. Given how corroded the originals had been, I slathered the news ones with some white lithium grease:

24) Attach new bumper bracket with bolts and washers.jpg (130.22 KiB) Viewed 11893 times

I adjusted them all the way up towards the top of their range and tightened up the bolts:

25) Position new bumper bracket towards top of adjustment range.jpg (106.94 KiB) Viewed 11893 times

I measured 130mm from the car body to the bottom of the bracket on both sides:

26) I measured 130mm between body and bottom of bumper bracket.jpg (115.63 KiB) Viewed 11893 times

After applying a couple of coats of paint to the bumper and letting it dry (~2 hrs on a very hot dry day), I lifted the bumper up and installed it on the new brackets:

27) Lift rear bumper up and into brackets.jpg (108.35 KiB) Viewed 11893 times

In the middle of the re-attachment process, the bumper looked like this, with an uneven gap:

27) Appearance of bumper gap during installation.jpg (61.49 KiB) Viewed 11893 times

Next I installed the new long vertical bolts and washers:

28) Install long bolts and washers into bumper brackets.jpg (123.93 KiB) Viewed 11893 times

Then I reinstalled the slip-bolts into their plastic keepers in the bumper wings on each side of the car:

29) Re-install slip-bolts into position inside the wing.jpg (73.95 KiB) Viewed 11893 times

Next I installed the 10mm bolt and washer inside the car on the driver's side. Some adjustment of the gap between the bumper and the car body can be made here if needed.

30) Install washer and 10mm bolt on driver's side (from inside car).jpg (81.5 KiB) Viewed 11893 times

And the 10mm bolt underneath the car on the passenger's side:

31) Install 10mm bolt on passenger's side (from under car).jpg (108.74 KiB) Viewed 11893 times

To re-attach the bumper wings to the wheel wheel liners I opted for brass machine screws and copper washers instead of plastic or aluminum rivets because I couldn't find a good inexpensive rivet gun.

32) Brass machine screws with copper washers instead of rivets.jpg (86.19 KiB) Viewed 11893 times

Installing the screws was somewhat difficult (I had to use 12" long needle nose pliers to hold the nuts in place while turning the screws). I might opt for a rivet gun the next time I have to do this job.

33) Screws installed to hold bumper wing to wheel well liner.jpg (92.41 KiB) Viewed 11893 times

A view of one of the screws from under the car, after installation:

33) Screw in place.jpg (105.8 KiB) Viewed 11893 times

Almost done! The final step is to re-attach the tailpipe:

34) Reinstall tailpipe.jpg (58.15 KiB) Viewed 11893 times

At the end of it all, it looked pretty good. The paint worked well and the bumper sag was eliminated. The gap looks pretty even all the way around.
Back:

35) Completed installation.jpg (109.66 KiB) Viewed 11893 times

Side:

36) Completed installation.jpg (79.76 KiB) Viewed 11893 times

[matthew1]

JReed, beautiful writeup. This = going in the VRD.

[byeboy]

Very nice writeup. You don't show any attention to curing the cause of the rust, especially when you experienced water running down that boy...Was there a way to dry it all out, the,block future water getting in there? I see you slathered that bracket in grease...but where did the water get in to start with?
Personal preference, but I simply drill rivet heads with a larger bit, which eats the heads right off, then allows me to just poke the rivet shafts through the hole. I also would have use stainless steel for the rivet replacement bolts..because it seems like the brass to copper to steel is just asking for galvanic corrosion. Not being at all critical, just kibitzing over your shoulder (which always drives me crazy! ).

Nice writeup. Thanks for taking the time to pass this along!

[m491]

Super timely port for me. My passenger side rear bumper is starting to sag a bit. I had a fair amount of rust on the exhaust hanger and fixed that this past winter. I did see a lot of rust on the passenger side and sure enough it must be starting to give.

The funny thing is the rust seems to only be on these replaceable brackets and no where else. All the body metal was is great shape. So I guess the source of this rust is 150-200,000 miles of use on these cars at this time in their life.

Thanks again for the great post.

[jreed]

Thanks for the comments and questions!
I would agree that the rust appeared to be contained to the brackets themselves plus the pitting on the long vertical bolts. Maybe the brackets are made out of steel and painted black without a galvanized zinc coating. I think the car body itself is fully galvanized to prevent rust.
Regarding the rivets, I too gave some thought to the issue of galvanic corrosion. I decided that since the wheel well liner and the bumper wing are made out of plastic (no steel involved) that it would be OK to use brass and copper. I'm going to keep my eye on the screws to see if they hold up or need replacing with rivets as you suggest. I did actually buy six of the 'official' Volvo plastic/aluminum pop rivets that are supposed to be used in those holes, but for the time being I couldn't find a good cheap rivet gun to install them. (I bought the $4 cheap-o Harbor Freight rivet gun but it jammed on the first rivet and I couldn't unjam it, so I took it back and got a refund).

[erikv11]

Here is a great alternative I recently learned about for fender liner rivets:

xmas_retainer.png (19.74 KiB) Viewed 11821 times

These "xmas tree retainers" are cheap, easy to use and bombproof, very common in the autobody business.

eBay is a good source or e.g. http://www.thecliplink.com/retainers/ch ... r-box.html

[pkc303]

Thank you so very much for your pictures. I was having trouble, as VADIS forgot to mention the 14mm bolts in the bumper. Finally got it off for repair, and repaint.

[jreed]

You're welcome. It was a fun job (in retrospect). Thanks for the feedback.

[conorf725]

what was the length of the long bolts that held the bumper to the brackets?