Spring Assisters
According to the manufacturers, the installation of spring assisters to the suspension leads to a far smoother ride, aids control of the vehicle (especially under load, or when towing) and reduces the risk of bottoming out. Allan Naysmith describes how he installed them.
I can expand a little on fitting adjustable air spring assisters to the rear suspension – the assisters are inflated individually and can be to different pressure on near side and off side if more weight is one side of vehicle. However I fitted mine for towing a caravan.
I ordered mine from Marcle Leisure, Huntley's Farm Lane, Much Marcle, Ledbury, Herefordshire HR8 2NB. Tel: 01531-660797. Website: www.marcleleisure.co.uk
They are held in stock at Marcle Leisure. The kit order code is MLA01129.
They were easy to fit after eventually figuring out how to fit first one inside the coil spring, fitting took about 4 hours
1 Jack up near side of vehicle from body to allow spring to expand (do not put jack under axle as this will keep spring compressed) and remove wheel.
Comment from Steve of Marcle leisure.
Please double check where you intend to lift the bodywork, as the sills are far too weak to support the vehicle. Use a designated jacking point or use the chassis. Once you have lifted your vehicle, for safety sake, use secondary supports to prevent any potential for the vehicle collapsing.
2 Remove bottom bolt on shock absorber to allow axle to drop a bit further as this increases the gap between the coils on spring.
3 The instructions supplied suggest fitting, approx 75mm of air pipe supplied in kit, and squeezing the spring assister balloon to expel air then fit plastic bung into pipe to retain in compressed state before offering up to spring but this makes the balloon hard and inflexible, I eventually found it much easier to fit without doing this as the balloon was much more flexible. Wipe spring assister balloon in washing up liquid to aid working thro gap at top of coil spring first push end with air pipe connection through gap between coils. It takes a bit of fiddling to get through and down inside the spring (don’t be tempted to push with stick etc as this may burst the balloon).
Comment from Steve of Marcle leisure.
Having read Allan's instructions on how he fitted the air bag in to the spring, I followed a slightly different route. After removal of the shock absorbers and dropping of the axle, I used a pair of spring compressors to squash the coils slightly, thus enabling easy removal and fitting of the air bag. This process was quite quick, but is dependant on the availability of specialist tools.
4 Once installed inside the coil fit the supplied thick flat plastic washer inside the bottom of the coil spring
Comment from Steve of Marcle leisure.
Looking at where the air bag was going to press top and bottom of the coil spring, I found some rough edges which I cleaned up to make smooth, as an extra precaution to help premature failure of the air bag, I made some extra washers out of floor vinyl (Lino as was called) to place the opposite end of the supplied thick washers (update, the new red kits are now supplied with 4 washers unlike the earlier kits only having 2 washers). Whilst you have access to the inside of the coil spring, do clean it up and check for sharp or rough edges and remove/make them smooth, as failure of the air bag through holes being caused by rough edges won’t be covered under warranty claims.
The airline goes down through the bottom support. If there is no pre-drilled hole, use a hole saw to cut one (approx 25mm diameter) and thoroughly de-burr the edges to avoid damage to the airline.
5 Decide where you want to locate the air valves to blow up / deflate pressure.
I fitted mine at step inside sliding door – remove the plastic step trim and drill a hole through the bottom of the metal step, fit a rubber grommet and route both air pipes under the chassis along the swing arm to the rear near side wheel, (at this time I also routed one air pipe, leaving a bit extra pipe - across the axle to the off side spring) secure air pipes using cable ties. Push the air pipe into the near side balloon (put felt pen mark on the pipe approx 18mm from the end and ensure pushed into balloon approx 15mm other wise the connection might leak, mine did and I had to jack up and remove wheel next day to push pipe further into fitting)
Comment from Steve of Marcle leisure.
The customer of the vehicle I worked on, also purchase a compressor kit for his vehicle (not part of the standard package). The optional extra consisted of a compressor with a dash mounted gauge and control switch. So instead of running the pipes to the door like Allan's installation, I ran both air bags to a tee connection, then ran a single hose along the chassis (add sleeving where the hose runs close to the exhaust) to under the bonnet where the compressor was mounted.
6 Refit bottom bolt to shock absorber, refit wheel and lower to ground
7 Jack up off side, remove wheel, remove shock absorber bolt and fit balloon as previously done on near side, cut and fit air pipe which you had previously routed and secured with cable ties, refit shock absorber bolt, refit wheel and lower to ground.
8 Inflate to required pressure ( I find 15 lbs pressure satisfactory for four adult passengers in the rear and 20lbs for towing) remember to deflate if putting vehicle into garage for repair as manufacture recommends deflation if jacking up vehicle from vehicle body – okay to leave inflated if jacking up from axle as air spring is still under compression.
9 Job done !!!!!!! when fully loaded driving over bumps no more bottoming on rubber axle buffers & vehicle stays level when towing.
Important note;
Before purchasing this product you need to be aware some Bongos have been lowered, some more than others! The bladders (air springs) in this kit will restore the ride height where the vehicle has sagged, however if the vehicle has been deliberately lowered by say 2 or 3 inches, this product is not suitable, you would need to fit some standard steel springs first.
The bladders in this kit are designed to sit inside the coil spring and its very important to maintain sufficient air pressure to maintain their shape. If the bladder is allowed to crumple or work its way out between the coils of the steel spring, the bladder must be deflated and repositioned, failure to maintain its correct working position will result in early failure. Damage to the bladder where it has been pinched between the coil spring, or allowed to bulge out between the coils will not be covered by any warrantee.
Last Amended 24th September 2006 followed by 10th May 2007 and again 17th August 2008 and again 15th October 2008. and again June 2009.