Before You Start

This guide covers the replacement of Bolec’s modern hand-adjustable roof clamps used on Jayco-style pop-top and Expanda caravans.
The clamps feature a tool-free tension tongue and fixed hook bracket for easy setup.

Tools & Materials

• Replacement Bolec roof clamp set (latch body + hook bracket + screws)
• Phillips or square-drive screwdriver (match supplied screws)
• Drill/driver + correct bit
• Masking tape or painter’s tape
• Exterior-grade caravan sealant or butyl (non-silicone)
• Rags + isopropyl alcohol or mineral turps (for cleaning)
• Permanent marker or pencil
• Safety glasses
• (Optional) No spanner needed — Bolec clamps use a hand-adjustable tongue instead of a nut.

Step 0. Safety / Setup

1. Park the caravan on level ground.
2. Keep the pop-top fully down and latched using the old clamps.
3. Turn off 12 V power so nothing moves accidentally.
4. Take clear photos of each existing clamp from the front, side, and underneath.

This preserves your original latch alignment and ensures the new clamps sit correctly.

Step 1. Replace One Clamp at a Time

Don’t remove all clamps at once. Replacing one at a time keeps the roof properly seated and prevents misalignment.

Step 2. Mark the Existing Clamp Position

1. Run masking tape around the base of the old clamp body on the caravan wall.
2. Trace around the clamp with a marker.
3. Mark where the hook meets the roof lip — this shows you the pull-down point.

Step 3. Remove the Old Clamp

1. While the clamp is still latched, slightly loosen the mounting screws (do not remove yet).
2. Unlatch the clamp and then remove the screws fully.
3. Detach the hook bracket from the roof frame if it’s a separate part.

If screws are rusted, drill the heads off carefully and extract the rest with pliers.

Step 4. Clean the Mounting Area

1. Remove any old sealant or tape residue.
2. Clean with isopropyl or mineral turps until dry.
3. Inspect for cracks or soft substrate — repair if necessary before refitting.

Step 5. Test-Fit the New Clamp

1. Position the new Bolec clamp body over your markings.
2. Check if screw holes line up — reuse if they do, or drill new pilots if required.
3. Ensure the hook engages naturally with the roof lip — no bending or twisting.
4. Close the latch by hand to check basic fit.

Step 6. Drill New Pilot Holes (If Needed)

1. Use a 2–3 mm drill bit to make small pilot holes for the new screws.
2. Drill slowly and shallow — avoid punching through internal lining or wiring.
3. Seal any unused old holes with exterior caravan sealant.

Step 7. Seal & Mount the New Clamp Body

1. Apply a thin bead of non-silicone caravan sealant or butyl around screw holes and under the base of the clamp.
2. Align the clamp body with your tape outline.
3. Insert screws by hand or on low torque until snug — do not overtighten.
4. Wipe off any excess sealant neatly.

Step 8. Adjust the Hand-Set Tongue Tension

Bolec clamps use a stepped hand-adjustable tongue instead of a threaded nut.
Adjustment is quick and tool-free:

1. Open the clamp and locate the tongue adjustment slot.
2. Lift or slide the tongue to the desired notch.
3. Close the clamp to test fit:
   • If too loose — move the tongue one step tighter.
   • If too tight — move it one step looser.
4. Repeat until the latch closes firmly with a positive snap, but without forcing.

Aim for firm compression on the roof seal — tight enough to stop vibration, not enough to deform panels.

Step 9. Repeat for Remaining Clamps

Install and adjust the opposite-corner clamp next to keep even tension, then continue around the van until all are replaced and evenly adjusted.

Step 10. Final Safety Check

1. Verify all clamps close fully and sit flat.
2. Push up gently near each clamp — the roof should not lift.
3. Inspect the perimeter seal; it should be evenly compressed.
4. After your first drive, recheck screw tightness and sealant for any gaps.

Troubleshooting

• Clamp doesn’t reach the hook: Shift the clamp body slightly down or use a different tongue notch.
• Roof feels uneven when shut: Balance tension across all clamps; don’t overtighten just one corner.
• Clamp opens too easily: Increase tension one notch until it locks positively over-centre.

When to Get Professional Help

• Mounting surface is rotten, soft, or water-damaged.
• Pop-top frame is cracked or separated.
• There’s visible water ingress or mould inside the wall near the clamp.

These issues require repair before reinstalling clamps — they affect both roof security and waterproofing.