A hydraulic bed fitting is the set of gas lift pistons and metal brackets that lets a heavy bed top rise and stay open. Shops may call it a hydraulic pump for bed, a hydraulic bed pump, a bed hydraulic lift or even a hydraulic jack for bed, but there is no pump or oil jack inside. It is a sealed gas piston that pushes outward and carries most of the lid's weight.
This page shows close-up pictures of the fittings and beds with them installed, then explains the force labels, how to match a pair to your lid and how to replace tired pistons. For bed styles, see the hydraulic bed design gallery.
Gas Lift Pistons: The Heart of a Bed Hydraulic Fitting
Every hydraulic for bed setup uses two pistons, one each side. They look alike but differ in length, stroke and force.
- SizeFits any size bed
- BuildSteel body, chrome rod
- StorageGas lift pair
A matched pair: same length, same force. Never mix a new piston with an old one, or the lid twists as it lifts.
Tell your carpenterBuy pistons as a pair and check both have identical length and force markings before fitting.
- SizeAny bed size
- BuildSteel, chrome rod
- StorageSingle gas piston
The shiny rod must stay clean and unscratched. A scratch on the rod lets gas leak out and the lift goes weak.
Tell your carpenterKeep paint, glue and polish off the chrome rod; wipe it dry and never oil it.
- SizeVaries by box depth
- BuildSteel, chrome rod
- StorageGas piston sizes
Pistons come in different lengths to suit the box depth and lid size. A wrong length either stops short or overshoots.
Tell your carpenterMeasure the old piston from eye to eye, closed and open, before buying a replacement.
Hydraulic Bed Lift Mechanism and Brackets
The piston needs strong brackets to push against. Many fittings come as a full lift mechanism with steel arms that guide the lid.
- SizeQueen and king lids
- BuildSteel arms, black paint
- StorageLift arm + piston
A full lift mechanism has hinged steel arms that guide the lid in a smooth arc. It suits large lids that need a steady path.
Tell your carpenterFix the mechanism plates with bolts through 18 mm ply, not short screws into the edge.
- SizeAny size
- BuildSteel bracket on ply
- StorageMounting bracket
The lower bracket sits on the inner side rail. Through bolts hold far better than wood screws when the lid is pushed open daily.
Tell your carpenterAsk for bolts with washers through the side rail; screws alone pull out of ply edges over time.
- SizeAny size
- BuildSteel bracket, ply lid
- StorageLid bracket
The upper bracket is screwed beneath the lid board. Its position decides how far the lid opens and how hard it pushes.
Tell your carpenterMark both lid brackets the same distance from the head end so the two pistons push evenly.
Beds with Hydraulic Lift Fitted and Open
Every bed fitting hydraulic or mechanical shows its quality once installed. Here are fittings at work on finished beds. Look at where the pistons sit and how far each lid opens.
- SizeDouble 48 x 75 in
- BuildPly, oak laminate
- StorageFull hydraulic lift
With the lid up you can see both pistons at the side rails and the clear box space between them.
Tell your carpenterOn delivery day, lift and lower the top several times: smooth travel, and it holds open unaided.
- SizeKing 72 x 78 in
- BuildPly, walnut laminate
- StorageTwo lids, two pairs
A split lid uses two pairs of pistons, one for each half. Each pair carries less, so each lid feels lighter.
Tell your carpenterEach half lid gets its own matched pair; do not share one piston between two lids.
- SizeSingle 36 x 75 in
- BuildPly, white laminate
- StorageSide lift hydraulic
This single bed lifts sideways, so the fittings sit on the head and foot rails instead of the long sides.
Tell your carpenterFor side lift, tell the fitter early; brackets go on the short rails and the lid hinges along the wall side.
Handles, Wall Bed Fittings and Replacement Parts
Small parts make daily use easier. A good handle and the right replacement keep the lift working for years.
- SizeAny size
- BuildPly, recessed metal pull
- StorageLid handle
A recessed handle gives a firm grip without a knob that catches bedsheets or shins.
Tell your carpenterFit the handle in the centre of the foot rail so the lid lifts evenly on both pistons.
- SizeDouble 48 x 75 in
- BuildSteel kit, ply cabinet
- StorageWall bed lift kit
Wall beds use their own lift kit sized for a vertical swing. It is a different fitting from a storage bed piston.
Tell your carpenterBuy the wall bed kit made for your bed size and fix the cabinet into a solid wall with anchors.
- SizeAny size
- BuildSteel, chrome rod
- StorageReplacement pair
Worn pistons slowly lose force over years. Replace both with the same length and rating, not just the weak one.
Tell your carpenterProp the lid with a strong stick before unscrewing the old piston, then fit the new ones one at a time.
Force Labels: 150 kg, 200 kg and 300 kg Hydraulic for Bed
Each strut carries a force figure. Hardware counters commonly stock 150, 200 and 300 kg versions. That figure tells you how hard the piston pushes, not the weight of the bed. Two things matter most:
- Per piston or per pair: find out which of the two the shopkeeper means. A pair marked 150 kg in total is weaker than two pistons marked 150 kg each.
- Match it to the lid: more board weight and a fatter mattress call for more force. A thin lid with a light mattress needs a lower one.
So a 150 kg hydraulic for bed is not always the weak choice and a 200 kg one is not always better. The best hydraulic for bed is the one that suits your lid.
Signs Your Hydraulic Bed Fittings Are Wrong or Worn
| What you see | Meaning | What to do |
|---|---|---|
| Lid springs up on its own | Lid too light for the pistons | Fit a lower rating, or add the real mattress before judging |
| Lid will not stay open | Lid too heavy, or pistons worn | Fit a higher rating or a new matched pair |
| Lid lifts crooked | Pistons unequal or brackets uneven | Replace both; reset brackets at equal distances |
| Oily mark on the rod | Seal leaking | Replace the pair |
| Clicking at the bracket | Loose bolt | Tighten and add a washer |
How to Replace a Bed Hydraulic Pump Safely
- Open the lid and prop it with a strong wooden stick or ask someone to hold it.
- Note the old piston's length closed and open, and its force label.
- Unclip or unscrew one piston at a time, rod side as per the old fitting.
- Fit the new piston the same way round as the old one.
- Repeat on the other side, then test with the mattress on.
Never cut, heat or puncture a gas piston. It is under pressure. Hand old ones to a scrap dealer as metal.
What Makes a Hydraulic Fitting Cost More or Less
- Higher force ratings and longer pistons cost more.
- A full steel lift mechanism costs more than pistons with simple brackets.
- Better rod plating and seals last longer and cost a little more.
- Two pairs for a split king lid double the parts.
For the bed itself, see what affects cost on our hydraulic bed page.
Questions people ask
Is a hydraulic pump bed fitting the same as a gas piston?
Yes. Shops say pump or jack, but the part is a sealed gas lift piston. It pushes the lid up; there is no oil pump.
Which is better, 150 kg or 200 kg hydraulic for bed?
Neither is better on its own. First learn whether the figure covers one strut or two, then pick by how heavy your lid and mattress are. Too strong springs up; too weak will not stay open.
How long does a bed hydraulic lift last?
Several years with normal use. Once the top begins sinking by itself, change the pair for two new ones of matching length and force.
Can I fit hydraulic to my old box bed?
Often yes, if the lid is a separate board and the side rails are strong ply or wood. A carpenter fixes brackets inside the box. See box bed designs for lid styles.
Is a wall mounted bed hydraulic fitting different?
Yes. A wall bed swings up vertically and uses a kit made for that bed size. Read our wall bed design page.
Can I mix one old and one new piston?
No. Unequal force twists the lid and strains the brackets. Always change both together.