The following CV Boot Repair Using a HippoRed Split CV Boot (80mm): Boot dimensions: Small diameter hole = 25mm, Large diameter hole = 79mm, Total Length = 100mm. The HippoRed Split CV Boot cost $41 each on Amazon with free shipping.

Note: I initially purchased the Bailcast Universal Split CV boot but the tongue-and-groove design of the split boot joint had only 1mm overlap between the two sides, which is minimal surface area for the glue to hold both sides together, so I returned the boots and ordered the HippoRed Split CV Boot instead.

My Car: 2000 ES300 V6 with aftermarket axles from previous repair. The large diameter side had the round configuration rather than the tri-lobe configuration. Both inner boots (left and right) ripped 2 months ago so I covered both ripped boots with plastic bag, duct tape, and zip ties to protect CV joints until I acquired all necessary repair equipment. This 2-boot repair took 5 hours.

The Good: Boot is made of nice thick rubber and appears to be durable. The tongue-and-groove design of the split boot joint is much more robust than the usual $20 universal boot and when joint is pushed together, it will hold together on its own so it is not necessary to hold the joint together with fingers until the glue dries (assuming the clamp groove on the axle is 25mm in diameter or less). However, I used a zip-tie in the middle of the boot to loosely hold the boot together until it dried (see photo). The amount of the included glue (Loctite Super Attak Power Flex Gel, 3 grams) is more than enough to do the job. It is a rubberized formula equivalent to the Loctite Super Glue Ultra Gel Control sold in the USA and is made for joining flexible materials like rubber. The glue takes a long time to dry; still tacky 2 hours after application even though the label says it will dry to touch in 30 seconds.

The Not So Good: The included stainless steel clamps are the strap-type clamps rather than the Oetiker-style crimp clamps which are preferred for ease of use.

Pro-Tips:
(1) Wipe axle surface very thoroughly with cloth and alcohol prior to pushing boot over axle. Apply masking tape to cover split joint on boot (see photo) to protect boot joint from contamination. Remove tape just prior to using glue.



(2) Obtain a plastic 50cc marinade/flavor meat injector ($5) to inject grease into CV joint. The hole in the needle should be large enough for thick grease to flow through. If there are several holes in the needle, cover extra holes with tape so the only open hole is at the tip. Put grease into device and put needle tip into CV joint and force grease into joint. If old grease is dirty, it must be removed first using Brake Cleaner spray. However, if it appears clean (the old grease in both of my CV joints appeared to be clean), I prefer to leave the old clean grease in-place and add more grease using the new grease included in the HippoRed package. IMHO, it is a greater concern to have too little grease in the CV joint than to worry about any chemical 'reaction' between the 2 different greases.

(3) Prior to tightening the clamps, the end of the clamp with the 3 teeth should be slightly bent downward/inward toward the center of the circle to assure the teeth engage the holes easily.

(4) Manually tighten the clamps as much as possible BEFORE using the tool to crimp the clamps because crimping only tightens the clamp an extra 8mm which is not much. If the clamps are too loose prior to crimping, it will be too loose after crimping as well. First, tighten the clamp by hand as much as possible, then attempt to tighten a bit more using a needle-nose plier (grip the clamp with tip of plier at the rectangular-shaped corner of the clamp and pull hard).




(5) Obtain screw-type clamp tool (see photo - it is clone of Toyota tool used at the factory), a package of Oetiker style crimp clamps (it is nice to have extra clamps in case a clamp or two get mangled in the crimping process), and also plier-style crimp tool - this is because sometimes, the screw-style tool slips over the rectangular crimp area of the clamp when starting the crimping process so using the plier-style tool to start the crimp process first may be necessary. However, since the plier-style tool requires a superhuman amount of hand strength to finish crimping, use the screw-style tool to finish the crimp - this is much easier. This screw-type clamp tool requires much less strength because the screw can be tightened easily, once the crimp is started.

(6) Because the glue takes a long time to fully cure, wait 1-2 days before driving.

 

I'm interested to see how that glue holds up.

 

The latest rubberized Loctite superglue appears to be the glue to use for rubber CV boots but since I have only driven a handful of miles since the repair, I need to wait and put more miles on the car before I can comment further. I will probably give an update in several months.

I am glad I returned the Bailcast Universal boots and went with the HippoRed boots for sure. One claim by HippoRed which i do not agree with is that their boot will fit an axle up to 29mm in diameter. Because the small diameter of the boot is 25mm, I tested this claim by getting a 29mm rod and trying to fit the HippoRed boot over it. The only way it would work is if I got a slip joint plier, opened it to the larger jaw setting, and used the plier and squeezed the split joint together by stretching the rubber. But then I would have to hold the joint together until the glue dried, which would have been way too long for my poor hands !

The aftermarket axles on my car had a diameter of 29mm but this measurement was taken in the middle of the axle. There is a groove on the axle which the small boot band is to be located. The function of the groove is to help the clamp to hold the boot. At the groove, the axle diameter was 26mm so I did need to squeeze the ends of the boot a little and hold it for several minutes but this situation was acceptable. But if the axle diameter at the groove had been 28mm or 29mm, this would have been a problem.

I have one more boot to repair: My 4runner 4WD. I will need a tri-lobe split CV boot (factory Toyota CV joint is tri-lobe as can be seen when I look at it). The split boot will be the expensive Miyaco M-Touch M-603G which costs $100 with shipping from Japan on Ebay. This high price makes the HippoRed look like a bargain at $41 on Amazon.
I already bought some rubberized Loctite superglue for the job:



Latest rubberlized superglue formula for gluing rubber.