EvaResto Premium Type 3 / 34 Rear Air Kit install Guide
Thank you for purchasing an EvaResto Air Suspension kit. This guide should tell you everything you need to know about fitting and operating your kit, but if you have any questions or are unsure of anything, feel free to email or call us and we’ll assist as soon as possible!
Please note:
Any work on the suspension system of your car is safety critical, and EvaResto LTD Strongly recommend this suspension system be installed by a Professional Automotive technician, ideally with prior experience fitting air suspension systems.
If you're unsure or inexperienced in this field, please seek the help of a professional installer!
EvaResto LTD takes no responsibility for faults that occur in the instance parts have been installed incorrectly or instructions not followed correctly!
This kit is designed as an easy to fit, well performing and highly practical air ride system for Type 3 cars. It is an ’independent’ kit and will replace the original style torsion bar setup in full.
Care must be taken out at every point to ensure the kit is installed correctly. Once it is in place, no ‘servicing’ of parts is required, but it is recommended that you check on the system periodically to make sure everything remains in top order.
Please note: This kit is designed for use with independent management types (4-way), and will perform it’s best if used as so. 2-way systems will operate it, however wont allow for the best performance
+ ride levelling available.
Parts list
Our kits are comprehensive and come with everything you need for proper installation.
We Recommend you take some time, familiarise yourself with the components and make sure you have everything present before you start the install.
Parts supplied:
Fastener kit:
All Necessary fixings are packed together.
Metric tools are required for install.
- 2x ‘U’ Bolts with Nyloc m8 nuts & Washers
- 8x 3/8” Bolts
- 2x M10x60 Bolts
- 12x M12x35 Bolts
- 2x M12x40 Bolts
- 4x M12x50 Bolts
- 4x M12x60 Bolts
- 2x 24mm Tube spacers
- 10x M10 Washers
- 44x M12 Washers
- 24x M12 Nyloc Nuts
Preparation
Get yourself and the car ready for the job.
Ensure vehicle is safely lifted and supported, using safe and correctly graded equipment. Wheels off, tools at the ready.
Note: Your kit may differ slightly in visual
design to the kit depicted in this fitting guide.
Car Preparation
Your original suspension system must be almost entirely removed for the new kit to be installed. Don’t worry though, there’s no cutting or fab work needed,
and the full kit is only bolt-on. Parts that will need removing entirely are:
- Shock Absorbers
- Spring Plates
- Torsion Bars
- Z Bar’/Rear anti roll bar assembly (if fitted)
- Rubber Bump stops and mounts
- Original brake hard lines from axle to hub
- Heat exchangers & tubes - Replace with J
Tubes.
With all of your existing setup removed, you should be left with something like this:
Now for the install guide...
Step 1
Installing the FreeRoll Air Ride Spring plates. The spring plates supplied with your kit are designed for use solely with independent air ride systems, and allow for full free movement, whilst keeping the alignment of the axle as true as possible. Install these plates with your original or repro original style rubber spring plate bushings.
Red Urethane bushings are a recommended if you'd like to replace for new. These must absolutely be installed with the correct type red 'rubber grease' for best operation.
Only re-use serviceable items, and
replace with new if you can see any signs of excessive wear.
Apply a good quality grease to the inside of the bushings and the spring plate stub, and install them like so:
Then re-fit them in the car using your original spring plate covers and fixings.
Repeat process for remaining side.
Step 2
Installing the Top Mount Halves. The top mount halves bolt to the shock
towers, torsion-tube, frame horns and each other.
The original M12 shock absorber top bolts must be re-used here, as they are a specific fine pitch thread. Use the supplied 24mm spacer tubes between the air ride top mount half, and the shock mounting like pictured
Pic showing original bolt and 24mm tube spacer
Install M12 bolt and tube spacer like shown, then lift Top Mount Half into position
Screw the bolt in by hand.
Next lift up the whole assembly and mate it to the torsion tube part of the chassis. Slip the U Bolt in place like pictured, and loosely secure in place with the m8 nuts and washers.
Move the top mount half into the correct (straight ahead) position, so that the 'leg' that connects the top mount to the torsion tube is as straight as possible. Then align the top shock mount fixings as close to the centre of the slotted mount as possible. Tighten down the M8 nuts on the U Bolt, and the Top M12 bolts fully.
Repeat this process for the other side. The top mount halves are now installed.
Step 3
Installing the Air Bags. Each Air bag has 2x upper fixings and 2x lower fixings. The Air port is in the upper plate, and will face the Top Mount. With 2x 3/8” bolts and M10 washers, install the bag into the Top Mount Half.
Note - Air bag mount holes are slotted for adjustability.
Install the air fittings before installing the bag, like shown.
The Air port fittings used are 1/8” npt to 1/4”
ptc (push to connect) 90deg fittings and require a good thread sealant for a fully air-tight seal. Use Loctite 565 or PTFE tape sparingly, and install the fitting into the port on the bag. These fittings are tapered type and need to be fitted finger tight + one full turn.
Set the bag at around mid-way of the slotted mounts, and tighten down fully (do not exceed 20 FT LBS tightening torque on these).
Repeat process for opposite Top Mount Half.
Step 4
Fitting the x-brace bar. The X-bar bolts between the two top mount halves with 4x M12x35 bolts, washers and nuts.
Slip the Brace bar into place between the top mounts, and secure in place loosely on one side with the M12 fixings. It doesn't matter if the bar is fitted in front or behind the flange on the top mount halves, as long as it's the same both sides! Repeat for the other side, then fully tighten down all 4x fixings.
Step 5
Fitting the Frame Horn Clamps. The Frame horn clamps are made up of 2x pieces each, and secured to the chassis with M12x35 fixings, washers and nuts.
Offer them in place like pictured, using the Lightning Bolt cut-out to help centralise them.
Mount them as close to the gearbox cradle as possible, then fully tighten down.
There is one clamp per chassis ‘horn’.
Step 6
Fitting the Stiffener bar assemblies. The stiffener bars help pre-load the top
mount assembly, making it as rigid as possible and helping to spread the suspension weight safely through the shock mounts, frame horns and torsion tube.
Bolt each stiffener bar in place using 4x M12x 35 fixings, 4x Washers (only needed on one side) and 4x nuts. Adjust the bars by twisting, to allow for no pre load either way (can be twisted by hand easily), then fully tighten down the M12 fixings.
In order to pre-load the top mount assembly, the stiffener bars must be tightened by hand, and then further (made shorter) by 1 full turn. Use the spanner flats machined into the rod, and once achieved, lock the assembly in place with the Jam nuts.
The top Mount is now fully installed.
Step 7
Fitting the Lower Bag Mounts. The lower bag mounts secure in place through
4 points. 3 being the spring plate-to-axle fixings, and the 4th being the original lower shock mount on the axle. They use 1x M12x40 bolt, 2x M12x50 Bolts and 1x M12x60 bolts per side. First up, lift the axle into the spring plate ‘cup’ and let it rest there, then offer up the lower Bag Mount.
Before fitting any of the fixings to the axle, get the 3/8” fittings and M10 washers, and locate them through the Bag Mount and into the threads on the base plate of the Bag.
You may need to lift the axle assembly upwards to allow easier access to the threaded holes in the base of the bag.
once the base plate 3/8” fixings are wound in enough to hold the bag in place, fit the M12x40 & M12x50 Bolts with washers through the Bag Mount, the spring plate, and the axle end casting. They absolutely must face with the threads facing outwards, to avoid any clearance issues with the bags.
The Lower Shock Absorber relocators can now be slipped into place over the M12x50 bolts like so:
With the Bag Mounts and Lower Shock Relocators in place, nuts and washers can be added.
Now locate the Lower shock mount on the end
casting and fit the M12x60 Fixings with
2x washers and Nut loosely for now.
The FreeRoll air ride spring plates are extended over stock units to allow for a corrected wheel toe angle when running low ride height, so with this in mind, set the rear toe adjustment about mid way in the adjustment slots on the spring plate. All the way back is to toe-out, and all the way forwards would be to toe-in.
Fully tighten the 3x M12 fixings on the spring plate once the alignment has been
matched side-to-side (left and right of the vehicle)
Once the other fixings are fully down, the M12x60 fixings for the original lower shock mount can be fully tightened down.
lastly, Tighten the 3/8” fittings for the Bags down, adjusting the bag to sit again mid-way between the ends of the slotted mounts, to match the top mount in alignment. It may be easier to do this with the hub/axle assembly lifted up a little (with a floor jack or similar).
Repeat process for opposite side.
The Lower bag mounts are now fitted.
Step 8
Fitting the new brake hard lines. You should have removed the old brake lines
in the 1st stage of removing the old suspension parts, or at least moved them out of the way for now. Supplied with the kit are new pre- made extended hard lines, made to pass ‘under’ the axle and spring plate rather than over it, eliminating any ‘over stretching’ of the flexi line during full drop, or any potential hang-ups with the hard line coming into contact with the inner wing of the car under the same circumstances.
Form the new brake line carefully by hand to follow the same path as shown below:
Note the brake line tab in the above picture. We have since designed a bolt-on version that uses the forwardmost air bag fixing bolt (visible in pic). Remove this bolt, and install the included brake line tab. These are sided so make sure you get them the right way around! These tabs allow for stock Type 3 flexi lines to be retained.
Once the brake lines are in place and connected up, use the factory clip to hold the flexi brake union in place. Do not allow the brake line to chafe on any parts!
Step 9
Fitting the shock absorbers. The Sport Gas shocks supplied are the perfect
specification and size for this kit, and allow for full range with no upgrade needed. The Shocks secure in place with M10x60 bolts up top and M12x60 Bolts + nuts at the bottom. Fit the shock absorbers as shown, and fully tighten down.
If possible, use thread locker on the top shock bolt fitting.
Step 10
Air Lines. The upper mount has a small hole in the front face that is sized perfectly for a 1/4” air line to pass through.
There are also small 3mm holes alongside the upright, that allow the line to be fitted with plastic P-clips (available as a full fitting kit on our web shop).
Pass the airline through the hole, connect it up to the PTC fitting, and ensure it’s in a safe location, away from sources of heat, movement or potential trapping.
The 4 holes towards the bottom of the top mount can also be used to secure the lines via cable ties.
Step 11
Final Bolt Check and Brake bleed. Bleed the brakes as you usually would when
replacing a small section of line. Once done, have a final check over all the parts
fitted, ensuring everything is properly tightened down, adjusted correctly and clearing. If you’re unsure of anything, please contact us!
Step 12
Set-up. Re-fit your wheels and pre-inflate the rear bags to around 70psi. lower the car off of the supports and ensure you’re clear of any obstructions underneath the car. Roll the car back and forwards slightly to allow things to settle. Now let the suspension down fully, allowing the bags to completely deflate and the car to reach maximum drop. There should be no hang-ups, and the car should sit level side-to-side and of course, look great.
Re-Inflate the bags to maximum (100psi) and support the car with a stand or chock (as for the next part you need to get underneath)
Get under the car as best you can (making sure if course the car is otherwise supported) and inspect the bags and the area around them. 100psi in the bags is the maximum they can take to be driven on, and at this pressure, you should expect a near-standard looking ride height. Look at the bags in relation to the axles and spring plates. All clear with no clearance issues? Brilliant. Otherwise, if it looks a little close for comfort (<5mm), jack the car back up, deflate the bags, and adjust them on the slotted mounts to sit further into the car.
This part is super important! It might be a pain to have to adjust the bags again, but they must NEVER contact or rub anything under their complete operating range! A Rub-free bag is one that will last for years to come.
Step 13
Selecting a good ride height. With the bags checked and adjusted for clearance if necessary, it's time to start operating the kit normally.
The Eva Premium kit is designed to be driven low, high, and everything in-between. A good starting point would be around 70psi in each bag. This should give around 3-4” of lift, great ride quality and ground clearance. You may need up to 10psi difference side-to-side to offset the weight of a single driver and no
passengers in order to maintain a level ride height, but this depends mainly on driver weight!
The kit should start to lift at around 35psi and can be driven low. But as a general rule with all air suspension systems, you should not operate the kit in the upper or lower 10% of it’s limits, as this can cause damage to the brackets, the chassis of your car, and the shock absorbers! Get a feel for the kit, and
experiment with different pressures and ride heights, to find what suits your driving style best.
Step 15
Now it’s time to rack up some miles on your newly-bagged VW. We recommend after the first 10, and then 50 miles or so to check over a few things, make sure nothing looks off, or has come loose. Once you’ve completed this period, standard service intervals apply, and your kit won’t need any special treatment, replacement parts or extra servicing for a good many years and thousands of miles.
We always recommend keeping an eye on the underside of your (most likely) 50+ year old classic car, but that’s just common sense ;).
