I am the proud owner of a 3 year old DS25 "Animal". I live in the USA in the Washington, DC area (Maryland Suburbs). My wife bought the "Animal" since we also have a beagle and a long hair Rottweiler.
Recently the Vac bounced down several stairs and one of the two wheels broke from the silver gray ABS plastic trolley casting. I was able to locate a new "trolley" without any difficulty at my local appliance center. The issue I found was when I took apart the vac - removed the old trolley and red pedal - a spring launched from the right side. When I was trying to reassemble the vac with the new trolley, I could not determine where that spring came from. It appeared to have been installed as part of the return mechanism on the red pedal.
I could not find where it reattached and reached out to the toll free phone line on a Saturday and got some expert advice from one of their call center support staff who actually went into the back room and brought out a vac and talked me through the procedure. What INCREDIBLY wonderful customer support! So, that my $550+ USD would continue in top condition, and for any others who have had the misfortune to bust a wheel off the non-gluable ABS trolley (a term I use - it is the part that the wheels are attached and is gray in color ) or otherwise have a reason to replace the trolley, I am posting photos and a quick narrative here since there is nothing on the DYSON website which illustrates the procedure.
(all narrative point of view is from the back, wheel side up if the vac waste holding tank were lying on a table or bench)
1. There are two long screws on the left side which need to be fully removed.
2. Two short screws and black washers need to be removed from the right side (see photo 1) Note that there is a flattened portion on each washer (see photo 2) and those must be re-positioned in their recesses when re-installing your new part.
3. Remove the red pedal and save the spring with is attached to the gray trolley on the right side only. My new trolley came with a larger spring (captive) attached to the left side. Upon removal of the old trolley, the left, larger spring was captive to the trolley.
When re-assembling I found it helpful to re-install and tighten the two longer screws on the left side first. Insert the red pedal left side into the molded cavity of the trolley for the metal rod which extends from the red pedal to ride in.
4. Reversing the order of removal, install the red pedal into the right side of the gray trolley using the same technique as you did when inserting the left. There is a small spring (the one you saved when you removed the red pedal from the old gray trolley) which if you weren't quick enough to see when you pulled it apart, goes into a recess on the right side of the red pedal one way only! (See photo 3)
5. It is not at all evident as to where the tang from the small spring attaches to the trolley (or any other part or parts for that matter). This necessitated my call to the Dyson Helpline. After inserting the small spring into the cavity on the right side of the red pedal, ensure that the spring is oriented correctly. (See photo 4). The "stud" end of the red pedal which captures the circular portion of the spring will be inserted into the gray trolley as shown in the photo. Insert one of the small screw and washer sets and loosely tighten - just enough to keep the two pieces connected, but to allow for positioning of the tang.
6. I found it helpful to also loosely attach the upper screw and washer as well. It is also helpful if you have someone hold the vac steady while doing this or you will not have enough hands to accomplish this feat. Prior to tightening the assembly finally, you need to use a needle nose piler to insert the tang end of the small spring against the flat area of the trolley. Photo 5 shows the area to which the tang needs to be placed . Then tighten any screws you left loose.
The small spring is used to pull the red pedal upwards when the trolley is raised for use.
I hope this helps anyone who gets as exasperated I was and felt I could figure out anything with a small bit of internet research. However, I could find nothing. Now, I feel, everything that is to know is now published with the addition of this posting.